Blame - docs/LangRef.html - fp2-dev/platform/external/llvm

blob: e578a0d8402f6d1d03a00e4af23a081ba6bf5d4d [file] [log] [blame]

Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1	<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
				2	"http://www.w3.org/TR/html4/strict.dtd">
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3	<html>
				4	<head>
				5	<title>LLVM Assembly Language Reference Manual</title>
Reid Spencer	3921c74	2004-08-26 20:44:00 +0000	[diff] [blame]	6	<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
				7	<meta name="author" content="Chris Lattner">
				8	<meta name="description"
				9	content="LLVM Assembly Language Reference Manual.">
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	10	<link rel="stylesheet" href="llvm.css" type="text/css">
				11	</head>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	12
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	13	<body>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	14
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	15	<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	16	<ol>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	17	<li><a href="#abstract">Abstract</a></li>
				18	<li><a href="#introduction">Introduction</a></li>
				19	<li><a href="#identifiers">Identifiers</a></li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	20	<li><a href="#highlevel">High Level Structure</a>
				21	<ol>
				22	<li><a href="#modulestructure">Module Structure</a></li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	23	<li><a href="#linkage">Linkage Types</a></li>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	24	<li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	25	<li><a href="#globalvars">Global Variables</a></li>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	26	<li><a href="#functionstructure">Functions</a></li>
Anton Korobeynikov	c6c98af	2007-04-29 18:02:48 +0000	[diff] [blame]	27	<li><a href="#aliasstructure">Aliases</a>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	28	<li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	29	<li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	30	<li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	31	<li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	32	<li><a href="#datalayout">Data Layout</a></li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	33	</ol>
				34	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	35	<li><a href="#typesystem">Type System</a>
				36	<ol>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	37	<li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	38	<li><a href="#t_primitive">Primitive Types</a>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	39	<ol>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	40	<li><a href="#t_floating">Floating Point Types</a></li>
				41	<li><a href="#t_void">Void Type</a></li>
				42	<li><a href="#t_label">Label Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	43	</ol>
				44	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	45	<li><a href="#t_derived">Derived Types</a>
				46	<ol>
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	47	<li><a href="#t_integer">Integer Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	48	<li><a href="#t_array">Array Type</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	49	<li><a href="#t_function">Function Type</a></li>
				50	<li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	51	<li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	52	<li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	53	<li><a href="#t_vector">Vector Type</a></li>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	54	<li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	55	</ol>
				56	</li>
				57	</ol>
				58	</li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	59	<li><a href="#constants">Constants</a>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	60	<ol>
				61	<li><a href="#simpleconstants">Simple Constants</a>
				62	<li><a href="#aggregateconstants">Aggregate Constants</a>
				63	<li><a href="#globalconstants">Global Variable and Function Addresses</a>
				64	<li><a href="#undefvalues">Undefined Values</a>
				65	<li><a href="#constantexprs">Constant Expressions</a>
				66	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	67	</li>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	68	<li><a href="#othervalues">Other Values</a>
				69	<ol>
				70	<li><a href="#inlineasm">Inline Assembler Expressions</a>
				71	</ol>
				72	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	73	<li><a href="#instref">Instruction Reference</a>
				74	<ol>
				75	<li><a href="#terminators">Terminator Instructions</a>
				76	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	77	<li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
				78	<li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	79	<li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
				80	<li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	81	<li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	82	<li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	83	</ol>
				84	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	85	<li><a href="#binaryops">Binary Operations</a>
				86	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	87	<li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
				88	<li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
				89	<li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	90	<li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
				91	<li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
				92	<li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	93	<li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
				94	<li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
				95	<li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	96	</ol>
				97	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	98	<li><a href="#bitwiseops">Bitwise Binary Operations</a>
				99	<ol>
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	100	<li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
				101	<li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
				102	<li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	103	<li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	104	<li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	105	<li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	106	</ol>
				107	</li>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	108	<li><a href="#vectorops">Vector Operations</a>
				109	<ol>
				110	<li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
				111	<li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
				112	<li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	113	</ol>
				114	</li>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	115	<li><a href="#aggregateops">Aggregate Operations</a>
				116	<ol>
				117	<li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
				118	<li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
				119	</ol>
				120	</li>
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	121	<li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	122	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	123	<li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
				124	<li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
				125	<li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	126	<li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
				127	<li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
				128	<li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	129	</ol>
				130	</li>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	131	<li><a href="#convertops">Conversion Operations</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	132	<ol>
				133	<li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
				134	<li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
				135	<li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
				136	<li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
				137	<li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	138	<li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
				139	<li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
				140	<li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
				141	<li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	142	<li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
				143	<li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	144	<li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	145	</ol>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	146	<li><a href="#otherops">Other Operations</a>
				147	<ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	148	<li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
				149	<li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	150	<li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
				151	<li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	152	<li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	153	<li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	154	<li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	155	<li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	156	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	157	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	158	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	159	</li>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	160	<li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	161	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	162	<li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
				163	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	164	<li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
				165	<li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
				166	<li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	167	</ol>
				168	</li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	169	<li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
				170	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	171	<li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
				172	<li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
				173	<li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	174	</ol>
				175	</li>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	176	<li><a href="#int_codegen">Code Generator Intrinsics</a>
				177	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	178	<li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
				179	<li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
				180	<li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
				181	<li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
				182	<li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
				183	<li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
				184	<li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell	7123e27	2004-04-09 16:43:20 +0000	[diff] [blame]	185	</ol>
				186	</li>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	187	<li><a href="#int_libc">Standard C Library Intrinsics</a>
				188	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	189	<li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
				190	<li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
				191	<li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
				192	<li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
				193	<li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	194	<li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
				195	<li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
				196	<li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	197	</ol>
				198	</li>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	199	<li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	200	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	201	<li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	202	<li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
				203	<li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
				204	<li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	205	<li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
				206	<li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	207	</ol>
				208	</li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	209	<li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	210	<li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	211	<li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	212	<ol>
				213	<li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	214	</ol>
				215	</li>
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	216	<li><a href="#int_atomics">Atomic intrinsics</a>
				217	<ol>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	218	<li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	219	<li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	220	<li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	221	<li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
				222	<li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
				223	<li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
				224	<li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
				225	<li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
				226	<li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
				227	<li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
				228	<li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
				229	<li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
				230	<li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	231	</ol>
				232	</li>
Reid Spencer	2067764	2007-07-20 19:59:11 +0000	[diff] [blame]	233	<li><a href="#int_general">General intrinsics</a>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	234	<ol>
Reid Spencer	2067764	2007-07-20 19:59:11 +0000	[diff] [blame]	235	<li><a href="#int_var_annotation">
Tanya Lattner	91d0b88	2007-09-22 00:01:26 +0000	[diff] [blame]	236	<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	237	<li><a href="#int_annotation">
Tanya Lattner	91d0b88	2007-09-22 00:01:26 +0000	[diff] [blame]	238	<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	239	<li><a href="#int_trap">
				240	<tt>llvm.trap</tt>' Intrinsic</a></li>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	241	</ol>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	242	</li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	243	</ol>
				244	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	245	</ol>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	246
				247	<div class="doc_author">
				248	<p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
				249	and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	250	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	251
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	252	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	253	<div class="doc_section"> <a name="abstract">Abstract </a></div>
				254	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	255
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	256	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	257	<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling	837f39b	2008-08-05 22:29:16 +0000	[diff] [blame]	258	LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	259	type safety, low-level operations, flexibility, and the capability of
				260	representing 'all' high-level languages cleanly. It is the common code
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	261	representation used throughout all phases of the LLVM compilation
				262	strategy.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	263	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	264
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	265	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	266	<div class="doc_section"> <a name="introduction">Introduction</a> </div>
				267	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	268
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	269	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	270
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	271	<p>The LLVM code representation is designed to be used in three
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	272	different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	273	representation (suitable for fast loading by a Just-In-Time compiler),
				274	and as a human readable assembly language representation. This allows
				275	LLVM to provide a powerful intermediate representation for efficient
				276	compiler transformations and analysis, while providing a natural means
				277	to debug and visualize the transformations. The three different forms
				278	of LLVM are all equivalent. This document describes the human readable
				279	representation and notation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	280
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	281	<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	282	while being expressive, typed, and extensible at the same time. It
				283	aims to be a "universal IR" of sorts, by being at a low enough level
				284	that high-level ideas may be cleanly mapped to it (similar to how
				285	microprocessors are "universal IR's", allowing many source languages to
				286	be mapped to them). By providing type information, LLVM can be used as
				287	the target of optimizations: for example, through pointer analysis, it
				288	can be proven that a C automatic variable is never accessed outside of
				289	the current function... allowing it to be promoted to a simple SSA
				290	value instead of a memory location.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	291
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	292	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	293
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	294	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	295	<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	296
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	297	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	298
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	299	<p>It is important to note that this document describes 'well formed'
				300	LLVM assembly language. There is a difference between what the parser
				301	accepts and what is considered 'well formed'. For example, the
				302	following instruction is syntactically okay, but not well formed:</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	303
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	304	<div class="doc_code">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	305	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	306	%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	307	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	308	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	309
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	310	<p>...because the definition of <tt>%x</tt> does not dominate all of
				311	its uses. The LLVM infrastructure provides a verification pass that may
				312	be used to verify that an LLVM module is well formed. This pass is
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	313	automatically run by the parser after parsing input assembly and by
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	314	the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	315	by the verifier pass indicate bugs in transformation passes or input to
				316	the parser.</p>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	317	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	318
Chris Lattner	cc68939	2007-10-03 17:34:29 +0000	[diff] [blame]	319	<!-- Describe the typesetting conventions here. -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	320
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	321	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	322	<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	323	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	324
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	325	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	326
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	327	<p>LLVM identifiers come in two basic types: global and local. Global
				328	identifiers (functions, global variables) begin with the @ character. Local
				329	identifiers (register names, types) begin with the % character. Additionally,
				330	there are three different formats for identifiers, for different purposes:
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	331
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	332	<ol>
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	333	<li>Named values are represented as a string of characters with their prefix.
				334	For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
				335	regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	336	Identifiers which require other characters in their names can be surrounded
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	337	with quotes. In this way, anything except a <tt>"</tt> character can
				338	be used in a named value.</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	339
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	340	<li>Unnamed values are represented as an unsigned numeric value with their
				341	prefix. For example, %12, @2, %44.</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	342
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	343	<li>Constants, which are described in a <a href="#constants">section about
				344	constants</a>, below.</li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	345	</ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	346
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	347	<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	348	don't need to worry about name clashes with reserved words, and the set of
				349	reserved words may be expanded in the future without penalty. Additionally,
				350	unnamed identifiers allow a compiler to quickly come up with a temporary
				351	variable without having to avoid symbol table conflicts.</p>
				352
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	353	<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	354	languages. There are keywords for different opcodes
				355	('<tt><a href="#i_add">add</a></tt>',
				356	'<tt><a href="#i_bitcast">bitcast</a></tt>',
				357	'<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names ('<tt><a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	358	href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	359	and others. These reserved words cannot conflict with variable names, because
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	360	none of them start with a prefix character ('%' or '@').</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	361
				362	<p>Here is an example of LLVM code to multiply the integer variable
				363	'<tt>%X</tt>' by 8:</p>
				364
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	365	<p>The easy way:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	366
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	367	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	368	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	369	%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	370	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	371	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	372
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	373	<p>After strength reduction:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	374
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	375	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	376	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	377	%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	378	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	379	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	380
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	381	<p>And the hard way:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	382
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	383	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	384	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	385	<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
				386	<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
				387	%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	388	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	389	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	390
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	391	<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
				392	important lexical features of LLVM:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	393
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	394	<ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	395
				396	<li>Comments are delimited with a '<tt>;</tt>' and go until the end of
				397	line.</li>
				398
				399	<li>Unnamed temporaries are created when the result of a computation is not
				400	assigned to a named value.</li>
				401
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	402	<li>Unnamed temporaries are numbered sequentially</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	403
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	404	</ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	405
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	406	<p>...and it also shows a convention that we follow in this document. When
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	407	demonstrating instructions, we will follow an instruction with a comment that
				408	defines the type and name of value produced. Comments are shown in italic
				409	text.</p>
				410
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	411	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	412
				413	<!-- *********************************************************************** -->
				414	<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
				415	<!-- *********************************************************************** -->
				416
				417	<!-- ======================================================================= -->
				418	<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
				419	</div>
				420
				421	<div class="doc_text">
				422
				423	<p>LLVM programs are composed of "Module"s, each of which is a
				424	translation unit of the input programs. Each module consists of
				425	functions, global variables, and symbol table entries. Modules may be
				426	combined together with the LLVM linker, which merges function (and
				427	global variable) definitions, resolves forward declarations, and merges
				428	symbol table entries. Here is an example of the "hello world" module:</p>
				429
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	430	<div class="doc_code">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	431	<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	432	<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
				433	href="#globalvars">constant</a> <a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	434
				435	<i>; External declaration of the puts function</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	436	<a href="#functionstructure">declare</a> i32 @puts(i8 ) <i>; i32(i8 )* </i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	437
				438	<i>; Definition of main function</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	439	define i32 @main() { <i>; i32()* </i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	440	<i>; Convert [13x i8 ]* to i8 *...</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	441	%cast210 = <a
Chris Lattner	6c0955b	2007-06-12 17:01:15 +0000	[diff] [blame]	442	href="#i_getelementptr">getelementptr</a> [13 x i8 ]* @.LC0, i64 0, i64 0 <i>; i8 *</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	443
				444	<i>; Call puts function to write out the string to stdout...</i>
				445	<a
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	446	href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	447	<a
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	448	href="#i_ret">ret</a> i32 0<br>}<br>
				449	</pre>
				450	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	451
				452	<p>This example is made up of a <a href="#globalvars">global variable</a>
				453	named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
				454	function, and a <a href="#functionstructure">function definition</a>
				455	for "<tt>main</tt>".</p>
				456
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	457	<p>In general, a module is made up of a list of global values,
				458	where both functions and global variables are global values. Global values are
				459	represented by a pointer to a memory location (in this case, a pointer to an
				460	array of char, and a pointer to a function), and have one of the following <a
				461	href="#linkage">linkage types</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	462
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	463	</div>
				464
				465	<!-- ======================================================================= -->
				466	<div class="doc_subsection">
				467	<a name="linkage">Linkage Types</a>
				468	</div>
				469
				470	<div class="doc_text">
				471
				472	<p>
				473	All Global Variables and Functions have one of the following types of linkage:
				474	</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	475
				476	<dl>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	477
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	478	<dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	479
				480	<dd>Global values with internal linkage are only directly accessible by
				481	objects in the current module. In particular, linking code into a module with
				482	an internal global value may cause the internal to be renamed as necessary to
				483	avoid collisions. Because the symbol is internal to the module, all
				484	references can be updated. This corresponds to the notion of the
Chris Lattner	4887bd8	2007-01-14 06:51:48 +0000	[diff] [blame]	485	'<tt>static</tt>' keyword in C.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	486	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	487
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	488	<dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	489
Chris Lattner	4887bd8	2007-01-14 06:51:48 +0000	[diff] [blame]	490	<dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
				491	the same name when linkage occurs. This is typically used to implement
				492	inline functions, templates, or other code which must be generated in each
				493	translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
				494	allowed to be discarded.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	495	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	496
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	497	<dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
				498
				499	<dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
				500	linkage, except that unreferenced <tt>common</tt> globals may not be
				501	discarded. This is used for globals that may be emitted in multiple
				502	translation units, but that are not guaranteed to be emitted into every
				503	translation unit that uses them. One example of this is tentative
				504	definitions in C, such as "<tt>int X;</tt>" at global scope.
				505	</dd>
				506
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	507	<dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	508
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	509	<dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
				510	that some targets may choose to emit different assembly sequences for them
				511	for target-dependent reasons. This is used for globals that are declared
				512	"weak" in C source code.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	513	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	514
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	515	<dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	516
				517	<dd>"<tt>appending</tt>" linkage may only be applied to global variables of
				518	pointer to array type. When two global variables with appending linkage are
				519	linked together, the two global arrays are appended together. This is the
				520	LLVM, typesafe, equivalent of having the system linker append together
				521	"sections" with identical names when .o files are linked.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	522	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	523
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	524	<dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	525	<dd>The semantics of this linkage follow the ELF object file model: the
				526	symbol is weak until linked, if not linked, the symbol becomes null instead
				527	of being an undefined reference.
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	528	</dd>
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	529
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	530	<dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	531
				532	<dd>If none of the above identifiers are used, the global is externally
				533	visible, meaning that it participates in linkage and can be used to resolve
				534	external symbol references.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	535	</dd>
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	536	</dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	537
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	538	<p>
				539	The next two types of linkage are targeted for Microsoft Windows platform
				540	only. They are designed to support importing (exporting) symbols from (to)
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	541	DLLs (Dynamic Link Libraries).
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	542	</p>
				543
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	544	<dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	545	<dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
				546
				547	<dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
				548	or variable via a global pointer to a pointer that is set up by the DLL
				549	exporting the symbol. On Microsoft Windows targets, the pointer name is
				550	formed by combining <code>_imp__</code> and the function or variable name.
				551	</dd>
				552
				553	<dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
				554
				555	<dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
				556	pointer to a pointer in a DLL, so that it can be referenced with the
				557	<tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
				558	name is formed by combining <code>_imp__</code> and the function or variable
				559	name.
				560	</dd>
				561
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	562	</dl>
				563
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	564	<p><a name="linkage_external"></a>For example, since the "<tt>.LC0</tt>"
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	565	variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
				566	variable and was linked with this one, one of the two would be renamed,
				567	preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
				568	external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer	ac8d276	2007-01-05 00:59:10 +0000	[diff] [blame]	569	outside of the current module.</p>
				570	<p>It is illegal for a function <i>declaration</i>
				571	to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	572	or <tt>extern_weak</tt>.</p>
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	573	<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
				574	linkages.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	575	</div>
				576
				577	<!-- ======================================================================= -->
				578	<div class="doc_subsection">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	579	<a name="callingconv">Calling Conventions</a>
				580	</div>
				581
				582	<div class="doc_text">
				583
				584	<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
				585	and <a href="#i_invoke">invokes</a> can all have an optional calling convention
				586	specified for the call. The calling convention of any pair of dynamic
				587	caller/callee must match, or the behavior of the program is undefined. The
				588	following calling conventions are supported by LLVM, and more may be added in
				589	the future:</p>
				590
				591	<dl>
				592	<dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
				593
				594	<dd>This calling convention (the default if no other calling convention is
				595	specified) matches the target C calling conventions. This calling convention
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	596	supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer	c28d2bc	2006-12-31 21:30:18 +0000	[diff] [blame]	597	prototype and implemented declaration of the function (as does normal C).
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	598	</dd>
				599
				600	<dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
				601
				602	<dd>This calling convention attempts to make calls as fast as possible
				603	(e.g. by passing things in registers). This calling convention allows the
				604	target to use whatever tricks it wants to produce fast code for the target,
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	605	without having to conform to an externally specified ABI (Application Binary
				606	Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer	9097d14	2008-05-14 09:17:12 +0000	[diff] [blame]	607	<a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
				608	supported. This calling convention does not support varargs and requires the
				609	prototype of all callees to exactly match the prototype of the function
				610	definition.
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	611	</dd>
				612
				613	<dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
				614
				615	<dd>This calling convention attempts to make code in the caller as efficient
				616	as possible under the assumption that the call is not commonly executed. As
				617	such, these calls often preserve all registers so that the call does not break
				618	any live ranges in the caller side. This calling convention does not support
				619	varargs and requires the prototype of all callees to exactly match the
				620	prototype of the function definition.
				621	</dd>
				622
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	623	<dt><b>"<tt>cc <<em>n</em>></tt>" - Numbered convention</b>:</dt>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	624
				625	<dd>Any calling convention may be specified by number, allowing
				626	target-specific calling conventions to be used. Target specific calling
				627	conventions start at 64.
				628	</dd>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	629	</dl>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	630
				631	<p>More calling conventions can be added/defined on an as-needed basis, to
				632	support pascal conventions or any other well-known target-independent
				633	convention.</p>
				634
				635	</div>
				636
				637	<!-- ======================================================================= -->
				638	<div class="doc_subsection">
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	639	<a name="visibility">Visibility Styles</a>
				640	</div>
				641
				642	<div class="doc_text">
				643
				644	<p>
				645	All Global Variables and Functions have one of the following visibility styles:
				646	</p>
				647
				648	<dl>
				649	<dt><b>"<tt>default</tt>" - Default style</b>:</dt>
				650
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	651	<dd>On targets that use the ELF object file format, default visibility means
				652	that the declaration is visible to other
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	653	modules and, in shared libraries, means that the declared entity may be
				654	overridden. On Darwin, default visibility means that the declaration is
				655	visible to other modules. Default visibility corresponds to "external
				656	linkage" in the language.
				657	</dd>
				658
				659	<dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
				660
				661	<dd>Two declarations of an object with hidden visibility refer to the same
				662	object if they are in the same shared object. Usually, hidden visibility
				663	indicates that the symbol will not be placed into the dynamic symbol table,
				664	so no other module (executable or shared library) can reference it
				665	directly.
				666	</dd>
				667
Anton Korobeynikov	6f9896f	2007-04-29 18:35:00 +0000	[diff] [blame]	668	<dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
				669
				670	<dd>On ELF, protected visibility indicates that the symbol will be placed in
				671	the dynamic symbol table, but that references within the defining module will
				672	bind to the local symbol. That is, the symbol cannot be overridden by another
				673	module.
				674	</dd>
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	675	</dl>
				676
				677	</div>
				678
				679	<!-- ======================================================================= -->
				680	<div class="doc_subsection">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	681	<a name="globalvars">Global Variables</a>
				682	</div>
				683
				684	<div class="doc_text">
				685
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	686	<p>Global variables define regions of memory allocated at compilation time
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	687	instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	688	an explicit section to be placed in, and may have an optional explicit alignment
				689	specified. A variable may be defined as "thread_local", which means that it
				690	will not be shared by threads (each thread will have a separated copy of the
				691	variable). A variable may be defined as a global "constant," which indicates
				692	that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	693	optimization, allowing the global data to be placed in the read-only section of
				694	an executable, etc). Note that variables that need runtime initialization
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	695	cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	696
				697	<p>
				698	LLVM explicitly allows <em>declarations</em> of global variables to be marked
				699	constant, even if the final definition of the global is not. This capability
				700	can be used to enable slightly better optimization of the program, but requires
				701	the language definition to guarantee that optimizations based on the
				702	'constantness' are valid for the translation units that do not include the
				703	definition.
				704	</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	705
				706	<p>As SSA values, global variables define pointer values that are in
				707	scope (i.e. they dominate) all basic blocks in the program. Global
				708	variables always define a pointer to their "content" type because they
				709	describe a region of memory, and all memory objects in LLVM are
				710	accessed through pointers.</p>
				711
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	712	<p>A global variable may be declared to reside in a target-specifc numbered
				713	address space. For targets that support them, address spaces may affect how
				714	optimizations are performed and/or what target instructions are used to access
Christopher Lamb	d49e18d	2007-12-12 08:44:39 +0000	[diff] [blame]	715	the variable. The default address space is zero. The address space qualifier
				716	must precede any other attributes.</p>
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	717
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	718	<p>LLVM allows an explicit section to be specified for globals. If the target
				719	supports it, it will emit globals to the section specified.</p>
				720
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	721	<p>An explicit alignment may be specified for a global. If not present, or if
				722	the alignment is set to zero, the alignment of the global is set by the target
				723	to whatever it feels convenient. If an explicit alignment is specified, the
				724	global is forced to have at least that much alignment. All alignments must be
				725	a power of 2.</p>
				726
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	727	<p>For example, the following defines a global in a numbered address space with
				728	an initializer, section, and alignment:</p>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	729
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	730	<div class="doc_code">
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	731	<pre>
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	732	@G = constant float 1.0 addrspace(5), section "foo", align 4
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	733	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	734	</div>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	735
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	736	</div>
				737
				738
				739	<!-- ======================================================================= -->
				740	<div class="doc_subsection">
				741	<a name="functionstructure">Functions</a>
				742	</div>
				743
				744	<div class="doc_text">
				745
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	746	<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
				747	an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	748	<a href="#visibility">visibility style</a>, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	749	<a href="#callingconv">calling convention</a>, a return type, an optional
				750	<a href="#paramattrs">parameter attribute</a> for the return type, a function
				751	name, a (possibly empty) argument list (each with optional
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	752	<a href="#paramattrs">parameter attributes</a>), optional
				753	<a href="#fnattrs">function attributes</a>, an optional section,
				754	an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattner	0c46a7d	2008-10-04 18:10:21 +0000	[diff] [blame]	755	an opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	756
				757	LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
				758	optional <a href="#linkage">linkage type</a>, an optional
				759	<a href="#visibility">visibility style</a>, an optional
				760	<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	761	<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	762	name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksen	e754abe	2007-12-10 03:30:21 +0000	[diff] [blame]	763	<a href="#gc">garbage collector name</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	764
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	765	<p>A function definition contains a list of basic blocks, forming the CFG
				766	(Control Flow Graph) for
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	767	the function. Each basic block may optionally start with a label (giving the
				768	basic block a symbol table entry), contains a list of instructions, and ends
				769	with a <a href="#terminators">terminator</a> instruction (such as a branch or
				770	function return).</p>
				771
Chris Lattner	4a3c901	2007-06-08 16:52:14 +0000	[diff] [blame]	772	<p>The first basic block in a function is special in two ways: it is immediately
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	773	executed on entrance to the function, and it is not allowed to have predecessor
				774	basic blocks (i.e. there can not be any branches to the entry block of a
				775	function). Because the block can have no predecessors, it also cannot have any
				776	<a href="#i_phi">PHI nodes</a>.</p>
				777
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	778	<p>LLVM allows an explicit section to be specified for functions. If the target
				779	supports it, it will emit functions to the section specified.</p>
				780
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	781	<p>An explicit alignment may be specified for a function. If not present, or if
				782	the alignment is set to zero, the alignment of the function is set by the target
				783	to whatever it feels convenient. If an explicit alignment is specified, the
				784	function is forced to have at least that much alignment. All alignments must be
				785	a power of 2.</p>
				786
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	787	<h5>Syntax:</h5>
				788
				789	<div class="doc_code">
Chris Lattner	50ad45c	2008-10-13 16:55:18 +0000	[diff] [blame]	790	<tt>
				791	define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
				792	[<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
				793	<ResultType> @<FunctionName> ([argument list])
				794	[<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
				795	[<a href="#gc">gc</a>] { ... }
				796	</tt>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	797	</div>
				798
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	799	</div>
				800
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	801
				802	<!-- ======================================================================= -->
				803	<div class="doc_subsection">
				804	<a name="aliasstructure">Aliases</a>
				805	</div>
				806	<div class="doc_text">
				807	<p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikov	726d45c	2008-03-22 08:36:14 +0000	[diff] [blame]	808	function, global variable, another alias or bitcast of global value). Aliases
				809	may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	810	optional <a href="#visibility">visibility style</a>.</p>
				811
				812	<h5>Syntax:</h5>
				813
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	814	<div class="doc_code">
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	815	<pre>
Duncan Sands	0b23ac1	2008-09-12 20:48:21 +0000	[diff] [blame]	816	@<Name> = alias [Linkage] [Visibility] <AliaseeTy> @<Aliasee>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	817	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	818	</div>
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	819
				820	</div>
				821
				822
				823
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	824	<!-- ======================================================================= -->
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	825	<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
				826	<div class="doc_text">
				827	<p>The return type and each parameter of a function type may have a set of
				828	<i>parameter attributes</i> associated with them. Parameter attributes are
				829	used to communicate additional information about the result or parameters of
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	830	a function. Parameter attributes are considered to be part of the function,
				831	not of the function type, so functions with different parameter attributes
				832	can have the same function type.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	833
Reid Spencer	950e9f8	2007-01-15 18:27:39 +0000	[diff] [blame]	834	<p>Parameter attributes are simple keywords that follow the type specified. If
				835	multiple parameter attributes are needed, they are space separated. For
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	836	example:</p>
				837
				838	<div class="doc_code">
				839	<pre>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	840	declare i32 @printf(i8* noalias , ...)
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	841	declare i32 @atoi(i8 zeroext)
				842	declare signext i8 @returns_signed_char()
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	843	</pre>
				844	</div>
				845
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	846	<p>Note that any attributes for the function result (<tt>nounwind</tt>,
				847	<tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	848
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	849	<p>Currently, only the following parameter attributes are defined:</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	850	<dl>
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	851	<dt><tt>zeroext</tt></dt>
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	852	<dd>This indicates to the code generator that the parameter or return value
				853	should be zero-extended to a 32-bit value by the caller (for a parameter)
				854	or the callee (for a return value).</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	855
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	856	<dt><tt>signext</tt></dt>
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	857	<dd>This indicates to the code generator that the parameter or return value
				858	should be sign-extended to a 32-bit value by the caller (for a parameter)
				859	or the callee (for a return value).</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	860
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	861	<dt><tt>inreg</tt></dt>
Dale Johannesen	c9c6da6	2008-09-25 20:47:45 +0000	[diff] [blame]	862	<dd>This indicates that this parameter or return value should be treated
				863	in a special target-dependent fashion during while emitting code for a
				864	function call or return (usually, by putting it in a register as opposed
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	865	to memory, though some targets use it to distinguish between two different
				866	kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	867
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	868	<dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner	0747baa	2008-01-15 04:34:22 +0000	[diff] [blame]	869	<dd>This indicates that the pointer parameter should really be passed by
				870	value to the function. The attribute implies that a hidden copy of the
				871	pointee is made between the caller and the callee, so the callee is unable
Chris Lattner	ebec678	2008-08-05 18:21:08 +0000	[diff] [blame]	872	to modify the value in the callee. This attribute is only valid on LLVM
Chris Lattner	0747baa	2008-01-15 04:34:22 +0000	[diff] [blame]	873	pointer arguments. It is generally used to pass structs and arrays by
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	874	value, but is also valid on pointers to scalars. The copy is considered to
				875	belong to the caller not the callee (for example,
				876	<tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	877	<tt>byval</tt> parameters). This is not a valid attribute for return
				878	values. </dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	879
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	880	<dt><tt>sret</tt></dt>
Duncan Sands	e26dec6	2008-02-18 04:19:38 +0000	[diff] [blame]	881	<dd>This indicates that the pointer parameter specifies the address of a
				882	structure that is the return value of the function in the source program.
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	883	This pointer must be guaranteed by the caller to be valid: loads and stores
				884	to the structure may be assumed by the callee to not to trap. This may only
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	885	be applied to the first parameter. This is not a valid attribute for
				886	return values. </dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	887
Zhou Sheng	febca34	2007-06-05 05:28:26 +0000	[diff] [blame]	888	<dt><tt>noalias</tt></dt>
Owen Anderson	117bbd3	2008-02-18 04:09:01 +0000	[diff] [blame]	889	<dd>This indicates that the parameter does not alias any global or any other
				890	parameter. The caller is responsible for ensuring that this is the case,
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	891	usually by placing the value in a stack allocation. This is not a valid
				892	attribute for return values.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	893
Duncan Sands	50f19f5	2007-07-27 19:57:41 +0000	[diff] [blame]	894	<dt><tt>nest</tt></dt>
Duncan Sands	0789b8b	2008-07-08 09:27:25 +0000	[diff] [blame]	895	<dd>This indicates that the pointer parameter can be excised using the
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	896	<a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
				897	attribute for return values.</dd>
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	898	</dl>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	899
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	900	</div>
				901
				902	<!-- ======================================================================= -->
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	903	<div class="doc_subsection">
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	904	<a name="gc">Garbage Collector Names</a>
				905	</div>
				906
				907	<div class="doc_text">
				908	<p>Each function may specify a garbage collector name, which is simply a
				909	string.</p>
				910
				911	<div class="doc_code"><pre
				912	>define void @f() gc "name" { ...</pre></div>
				913
				914	<p>The compiler declares the supported values of <i>name</i>. Specifying a
				915	collector which will cause the compiler to alter its output in order to support
				916	the named garbage collection algorithm.</p>
				917	</div>
				918
				919	<!-- ======================================================================= -->
				920	<div class="doc_subsection">
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	921	<a name="fnattrs">Function Attributes</a>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	922	</div>
				923
				924	<div class="doc_text">
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	925
				926	<p>Function attributes are set to communicate additional information about
				927	a function. Function attributes are considered to be part of the function,
				928	not of the function type, so functions with different parameter attributes
				929	can have the same function type.</p>
				930
				931	<p>Function attributes are simple keywords that follow the type specified. If
				932	multiple attributes are needed, they are space separated. For
				933	example:</p>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	934
				935	<div class="doc_code">
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	936	<pre>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	937	define void @f() noinline { ... }
				938	define void @f() alwaysinline { ... }
				939	define void @f() alwaysinline optsize { ... }
				940	define void @f() optsize
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	941	</pre>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	942	</div>
				943
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	944	<dl>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	945	<dt><tt>alwaysinline</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	946	<dd>This attribute indicates that the inliner should attempt to inline this
				947	function into callers whenever possible, ignoring any active inlining size
				948	threshold for this caller.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	949
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	950	<dt><tt>noinline</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	951	<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner	94b5f7d	2008-10-05 17:14:59 +0000	[diff] [blame]	952	in any situation. This attribute may not be used together with the
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	953	<tt>alwaysinline</tt> attribute.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	954
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	955	<dt><tt>optsize</tt></dt>
Devang Patel	66c6c65	2008-09-29 18:34:44 +0000	[diff] [blame]	956	<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	957	make choices that keep the code size of this function low, and otherwise do
				958	optimizations specifically to reduce code size.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	959
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	960	<dt><tt>noreturn</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	961	<dd>This function attribute indicates that the function never returns normally.
				962	This produces undefined behavior at runtime if the function ever does
				963	dynamically return.</dd>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	964
				965	<dt><tt>nounwind</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	966	<dd>This function attribute indicates that the function never returns with an
				967	unwind or exceptional control flow. If the function does unwind, its runtime
				968	behavior is undefined.</dd>
				969
				970	<dt><tt>readnone</tt></dt>
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	971	<dd>This attribute indicates that the function computes its result (or the
				972	exception it throws) based strictly on its arguments, without dereferencing any
				973	pointer arguments or otherwise accessing any mutable state (e.g. memory, control
				974	registers, etc) visible to caller functions. It does not write through any
				975	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
				976	never changes any state visible to callers.</dd>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	977
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	978	<dt><tt><a name="readonly">readonly</a></tt></dt>
				979	<dd>This attribute indicates that the function does not write through any
				980	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
				981	or otherwise modify any state (e.g. memory, control registers, etc) visible to
				982	caller functions. It may dereference pointer arguments and read state that may
				983	be set in the caller. A readonly function always returns the same value (or
				984	throws the same exception) when called with the same set of arguments and global
				985	state.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	986	</dl>
				987
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	988	</div>
				989
				990	<!-- ======================================================================= -->
				991	<div class="doc_subsection">
Chris Lattner	1eeeb0c	2006-04-08 04:40:53 +0000	[diff] [blame]	992	<a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	993	</div>
				994
				995	<div class="doc_text">
				996	<p>
				997	Modules may contain "module-level inline asm" blocks, which corresponds to the
				998	GCC "file scope inline asm" blocks. These blocks are internally concatenated by
				999	LLVM and treated as a single unit, but may be separated in the .ll file if
				1000	desired. The syntax is very simple:
				1001	</p>
				1002
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1003	<div class="doc_code">
				1004	<pre>
				1005	module asm "inline asm code goes here"
				1006	module asm "more can go here"
				1007	</pre>
				1008	</div>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	1009
				1010	<p>The strings can contain any character by escaping non-printable characters.
				1011	The escape sequence used is simply "\xx" where "xx" is the two digit hex code
				1012	for the number.
				1013	</p>
				1014
				1015	<p>
				1016	The inline asm code is simply printed to the machine code .s file when
				1017	assembly code is generated.
				1018	</p>
				1019	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1020
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1021	<!-- ======================================================================= -->
				1022	<div class="doc_subsection">
				1023	<a name="datalayout">Data Layout</a>
				1024	</div>
				1025
				1026	<div class="doc_text">
				1027	<p>A module may specify a target specific data layout string that specifies how
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	1028	data is to be laid out in memory. The syntax for the data layout is simply:</p>
				1029	<pre> target datalayout = "<i>layout specification</i>"</pre>
				1030	<p>The <i>layout specification</i> consists of a list of specifications
				1031	separated by the minus sign character ('-'). Each specification starts with a
				1032	letter and may include other information after the letter to define some
				1033	aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1034	<dl>
				1035	<dt><tt>E</tt></dt>
				1036	<dd>Specifies that the target lays out data in big-endian form. That is, the
				1037	bits with the most significance have the lowest address location.</dd>
				1038	<dt><tt>e</tt></dt>
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1039	<dd>Specifies that the target lays out data in little-endian form. That is,
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1040	the bits with the least significance have the lowest address location.</dd>
				1041	<dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1042	<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
				1043	<i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
				1044	alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
				1045	too.</dd>
				1046	<dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1047	<dd>This specifies the alignment for an integer type of a given bit
				1048	<i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
				1049	<dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1050	<dd>This specifies the alignment for a vector type of a given bit
				1051	<i>size</i>.</dd>
				1052	<dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1053	<dd>This specifies the alignment for a floating point type of a given bit
				1054	<i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
				1055	(double).</dd>
				1056	<dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1057	<dd>This specifies the alignment for an aggregate type of a given bit
				1058	<i>size</i>.</dd>
				1059	</dl>
				1060	<p>When constructing the data layout for a given target, LLVM starts with a
				1061	default set of specifications which are then (possibly) overriden by the
				1062	specifications in the <tt>datalayout</tt> keyword. The default specifications
				1063	are given in this list:</p>
				1064	<ul>
				1065	<li><tt>E</tt> - big endian</li>
				1066	<li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
				1067	<li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
				1068	<li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
				1069	<li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
				1070	<li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1071	<li><tt>i64:32:64</tt> - i64 has ABI alignment of 32-bits but preferred
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1072	alignment of 64-bits</li>
				1073	<li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
				1074	<li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
				1075	<li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
				1076	<li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
				1077	<li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
				1078	</ul>
Chris Lattner	ebec678	2008-08-05 18:21:08 +0000	[diff] [blame]	1079	<p>When LLVM is determining the alignment for a given type, it uses the
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1080	following rules:
				1081	<ol>
				1082	<li>If the type sought is an exact match for one of the specifications, that
				1083	specification is used.</li>
				1084	<li>If no match is found, and the type sought is an integer type, then the
				1085	smallest integer type that is larger than the bitwidth of the sought type is
				1086	used. If none of the specifications are larger than the bitwidth then the the
				1087	largest integer type is used. For example, given the default specifications
				1088	above, the i7 type will use the alignment of i8 (next largest) while both
				1089	i65 and i256 will use the alignment of i64 (largest specified).</li>
				1090	<li>If no match is found, and the type sought is a vector type, then the
				1091	largest vector type that is smaller than the sought vector type will be used
				1092	as a fall back. This happens because <128 x double> can be implemented in
				1093	terms of 64 <2 x double>, for example.</li>
				1094	</ol>
				1095	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1096
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1097	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1098	<div class="doc_section"> <a name="typesystem">Type System</a> </div>
				1099	<!-- *********************************************************************** -->
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1100
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1101	<div class="doc_text">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1102
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1103	<p>The LLVM type system is one of the most important features of the
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1104	intermediate representation. Being typed enables a number of
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1105	optimizations to be performed on the intermediate representation directly,
				1106	without having to do
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1107	extra analyses on the side before the transformation. A strong type
				1108	system makes it easier to read the generated code and enables novel
				1109	analyses and transformations that are not feasible to perform on normal
				1110	three address code representations.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1111
				1112	</div>
				1113
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1114	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1115	<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1116	Classifications</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1117	<div class="doc_text">
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1118	<p>The types fall into a few useful
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1119	classifications:</p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1120
				1121	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1122	<tbody>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1123	<tr><th>Classification</th><th>Types</th></tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1124	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1125	<td><a href="#t_integer">integer</a></td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1126	<td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1127	</tr>
				1128	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1129	<td><a href="#t_floating">floating point</a></td>
				1130	<td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1131	</tr>
				1132	<tr>
				1133	<td><a name="t_firstclass">first class</a></td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1134	<td><a href="#t_integer">integer</a>,
				1135	<a href="#t_floating">floating point</a>,
				1136	<a href="#t_pointer">pointer</a>,
Dan Gohman	0066db6	2008-06-18 18:42:13 +0000	[diff] [blame]	1137	<a href="#t_vector">vector</a>,
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	1138	<a href="#t_struct">structure</a>,
				1139	<a href="#t_array">array</a>,
Dan Gohman	ade5faa	2008-05-23 22:50:26 +0000	[diff] [blame]	1140	<a href="#t_label">label</a>.
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1141	</td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1142	</tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1143	<tr>
				1144	<td><a href="#t_primitive">primitive</a></td>
				1145	<td><a href="#t_label">label</a>,
				1146	<a href="#t_void">void</a>,
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1147	<a href="#t_floating">floating point</a>.</td>
				1148	</tr>
				1149	<tr>
				1150	<td><a href="#t_derived">derived</a></td>
				1151	<td><a href="#t_integer">integer</a>,
				1152	<a href="#t_array">array</a>,
				1153	<a href="#t_function">function</a>,
				1154	<a href="#t_pointer">pointer</a>,
				1155	<a href="#t_struct">structure</a>,
				1156	<a href="#t_pstruct">packed structure</a>,
				1157	<a href="#t_vector">vector</a>,
				1158	<a href="#t_opaque">opaque</a>.
Dan Gohman	01ac101	2008-10-14 16:32:04 +0000	[diff] [blame^]	1159	</td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1160	</tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1161	</tbody>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1162	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1163
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1164	<p>The <a href="#t_firstclass">first class</a> types are perhaps the
				1165	most important. Values of these types are the only ones which can be
				1166	produced by instructions, passed as arguments, or used as operands to
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	1167	instructions.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1168	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1169
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1170	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1171	<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1172
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1173	<div class="doc_text">
				1174	<p>The primitive types are the fundamental building blocks of the LLVM
				1175	system.</p>
				1176
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1177	</div>
				1178
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1179	<!-- _______________________________________________________________________ -->
				1180	<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
				1181
				1182	<div class="doc_text">
				1183	<table>
				1184	<tbody>
				1185	<tr><th>Type</th><th>Description</th></tr>
				1186	<tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
				1187	<tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
				1188	<tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
				1189	<tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
				1190	<tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
				1191	</tbody>
				1192	</table>
				1193	</div>
				1194
				1195	<!-- _______________________________________________________________________ -->
				1196	<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
				1197
				1198	<div class="doc_text">
				1199	<h5>Overview:</h5>
				1200	<p>The void type does not represent any value and has no size.</p>
				1201
				1202	<h5>Syntax:</h5>
				1203
				1204	<pre>
				1205	void
				1206	</pre>
				1207	</div>
				1208
				1209	<!-- _______________________________________________________________________ -->
				1210	<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
				1211
				1212	<div class="doc_text">
				1213	<h5>Overview:</h5>
				1214	<p>The label type represents code labels.</p>
				1215
				1216	<h5>Syntax:</h5>
				1217
				1218	<pre>
				1219	label
				1220	</pre>
				1221	</div>
				1222
				1223
				1224	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1225	<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1226
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1227	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1228
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1229	<p>The real power in LLVM comes from the derived types in the system.
				1230	This is what allows a programmer to represent arrays, functions,
				1231	pointers, and other useful types. Note that these derived types may be
				1232	recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1233
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1234	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1235
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1236	<!-- _______________________________________________________________________ -->
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1237	<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
				1238
				1239	<div class="doc_text">
				1240
				1241	<h5>Overview:</h5>
				1242	<p>The integer type is a very simple derived type that simply specifies an
				1243	arbitrary bit width for the integer type desired. Any bit width from 1 bit to
				1244	2^23-1 (about 8 million) can be specified.</p>
				1245
				1246	<h5>Syntax:</h5>
				1247
				1248	<pre>
				1249	iN
				1250	</pre>
				1251
				1252	<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
				1253	value.</p>
				1254
				1255	<h5>Examples:</h5>
				1256	<table class="layout">
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	1257	<tbody>
				1258	<tr>
				1259	<td><tt>i1</tt></td>
				1260	<td>a single-bit integer.</td>
				1261	</tr><tr>
				1262	<td><tt>i32</tt></td>
				1263	<td>a 32-bit integer.</td>
				1264	</tr><tr>
				1265	<td><tt>i1942652</tt></td>
				1266	<td>a really big integer of over 1 million bits.</td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1267	</tr>
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	1268	</tbody>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1269	</table>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1270	</div>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1271
				1272	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1273	<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1274
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1275	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1276
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1277	<h5>Overview:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1278
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1279	<p>The array type is a very simple derived type that arranges elements
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1280	sequentially in memory. The array type requires a size (number of
				1281	elements) and an underlying data type.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1282
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1283	<h5>Syntax:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1284
				1285	<pre>
				1286	[<# elements> x <elementtype>]
				1287	</pre>
				1288
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1289	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1290	be any type with a size.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1291
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1292	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1293	<table class="layout">
				1294	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1295	<td class="left"><tt>[40 x i32]</tt></td>
				1296	<td class="left">Array of 40 32-bit integer values.</td>
				1297	</tr>
				1298	<tr class="layout">
				1299	<td class="left"><tt>[41 x i32]</tt></td>
				1300	<td class="left">Array of 41 32-bit integer values.</td>
				1301	</tr>
				1302	<tr class="layout">
				1303	<td class="left"><tt>[4 x i8]</tt></td>
				1304	<td class="left">Array of 4 8-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1305	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1306	</table>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1307	<p>Here are some examples of multidimensional arrays:</p>
				1308	<table class="layout">
				1309	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1310	<td class="left"><tt>[3 x [4 x i32]]</tt></td>
				1311	<td class="left">3x4 array of 32-bit integer values.</td>
				1312	</tr>
				1313	<tr class="layout">
				1314	<td class="left"><tt>[12 x [10 x float]]</tt></td>
				1315	<td class="left">12x10 array of single precision floating point values.</td>
				1316	</tr>
				1317	<tr class="layout">
				1318	<td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
				1319	<td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1320	</tr>
				1321	</table>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1322
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1323	<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
				1324	length array. Normally, accesses past the end of an array are undefined in
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1325	LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
				1326	As a special case, however, zero length arrays are recognized to be variable
				1327	length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1328	type "{ i32, [0 x float]}", for example.</p>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1329
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1330	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1331
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1332	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1333	<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1334	<div class="doc_text">
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1335
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1336	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1337
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1338	<p>The function type can be thought of as a function signature. It
Devang Patel	a582f40	2008-03-24 05:35:41 +0000	[diff] [blame]	1339	consists of a return type and a list of formal parameter types. The
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1340	return type of a function type is a scalar type, a void type, or a struct type.
Devang Patel	7a3ad1a	2008-03-24 20:52:42 +0000	[diff] [blame]	1341	If the return type is a struct type then all struct elements must be of first
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1342	class types, and the struct must have at least one element.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1343
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1344	<h5>Syntax:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1345
				1346	<pre>
				1347	<returntype list> (<parameter list>)
				1348	</pre>
				1349
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1350	<p>...where '<tt><parameter list></tt>' is a comma-separated list of type
Misha Brukman	c24b758	2004-08-12 20:16:08 +0000	[diff] [blame]	1351	specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	1352	which indicates that the function takes a variable number of arguments.
				1353	Variable argument functions can access their arguments with the <a
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1354	href="#int_varargs">variable argument handling intrinsic</a> functions.
				1355	'<tt><returntype list></tt>' is a comma-separated list of
				1356	<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1357
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1358	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1359	<table class="layout">
				1360	<tr class="layout">
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1361	<td class="left"><tt>i32 (i32)</tt></td>
				1362	<td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1363	</td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1364	</tr><tr class="layout">
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	1365	<td class="left"><tt>float (i16 signext, i32 )
Reid Spencer	f17a0b7	2006-12-31 07:20:23 +0000	[diff] [blame]	1366	</tt></td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1367	<td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
				1368	an <tt>i16</tt> that should be sign extended and a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1369	<a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1370	<tt>float</tt>.
				1371	</td>
				1372	</tr><tr class="layout">
				1373	<td class="left"><tt>i32 (i8*, ...)</tt></td>
				1374	<td class="left">A vararg function that takes at least one
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1375	<a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1376	which returns an integer. This is the signature for <tt>printf</tt> in
				1377	LLVM.
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1378	</td>
Devang Patel	a582f40	2008-03-24 05:35:41 +0000	[diff] [blame]	1379	</tr><tr class="layout">
				1380	<td class="left"><tt>{i32, i32} (i32)</tt></td>
Devang Patel	3a5bff8	2008-03-24 18:10:52 +0000	[diff] [blame]	1381	<td class="left">A function taking an <tt>i32></tt>, returning two
				1382	<tt> i32 </tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patel	a582f40	2008-03-24 05:35:41 +0000	[diff] [blame]	1383	</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1384	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1385	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1386
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1387	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1388	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1389	<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1390	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1391	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1392	<p>The structure type is used to represent a collection of data members
				1393	together in memory. The packing of the field types is defined to match
				1394	the ABI of the underlying processor. The elements of a structure may
				1395	be any type that has a size.</p>
				1396	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1397	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1398	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1399	instruction.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1400	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1401	<pre> { <type list> }<br></pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1402	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1403	<table class="layout">
				1404	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1405	<td class="left"><tt>{ i32, i32, i32 }</tt></td>
				1406	<td class="left">A triple of three <tt>i32</tt> values</td>
				1407	</tr><tr class="layout">
				1408	<td class="left"><tt>{ float, i32 (i32) * }</tt></td>
				1409	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1410	second element is a <a href="#t_pointer">pointer</a> to a
				1411	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1412	an <tt>i32</tt>.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1413	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1414	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1415	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1416
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1417	<!-- _______________________________________________________________________ -->
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1418	<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
				1419	</div>
				1420	<div class="doc_text">
				1421	<h5>Overview:</h5>
				1422	<p>The packed structure type is used to represent a collection of data members
				1423	together in memory. There is no padding between fields. Further, the alignment
				1424	of a packed structure is 1 byte. The elements of a packed structure may
				1425	be any type that has a size.</p>
				1426	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1427	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1428	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1429	instruction.</p>
				1430	<h5>Syntax:</h5>
				1431	<pre> < { <type list> } > <br></pre>
				1432	<h5>Examples:</h5>
				1433	<table class="layout">
				1434	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1435	<td class="left"><tt>< { i32, i32, i32 } ></tt></td>
				1436	<td class="left">A triple of three <tt>i32</tt> values</td>
				1437	</tr><tr class="layout">
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1438	<td class="left">
				1439	<tt>< { float, i32 (i32)* } ></tt></td>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1440	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1441	second element is a <a href="#t_pointer">pointer</a> to a
				1442	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1443	an <tt>i32</tt>.</td>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1444	</tr>
				1445	</table>
				1446	</div>
				1447
				1448	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1449	<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1450	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1451	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1452	<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	1453	reference to another object, which must live in memory. Pointer types may have
				1454	an optional address space attribute defining the target-specific numbered
				1455	address space where the pointed-to object resides. The default address space is
				1456	zero.</p>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1457	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1458	<pre> <type> *<br></pre>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1459	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1460	<table class="layout">
				1461	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1462	<td class="left"><tt>[4x i32]*</tt></td>
				1463	<td class="left">A <a href="#t_pointer">pointer</a> to <a
				1464	href="#t_array">array</a> of four <tt>i32</tt> values.</td>
				1465	</tr>
				1466	<tr class="layout">
				1467	<td class="left"><tt>i32 (i32 ) </tt></td>
				1468	<td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1469	href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1470	<tt>i32</tt>.</td>
				1471	</tr>
				1472	<tr class="layout">
				1473	<td class="left"><tt>i32 addrspace(5)*</tt></td>
				1474	<td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
				1475	that resides in address space #5.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1476	</tr>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1477	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1478	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1479
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1480	<!-- _______________________________________________________________________ -->
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1481	<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1482	<div class="doc_text">
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1483
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1484	<h5>Overview:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1485
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1486	<p>A vector type is a simple derived type that represents a vector
				1487	of elements. Vector types are used when multiple primitive data
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1488	are operated in parallel using a single instruction (SIMD).
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1489	A vector type requires a size (number of
Chris Lattner	b8d172f	2005-11-10 01:44:22 +0000	[diff] [blame]	1490	elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1491	of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1492	considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1493
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1494	<h5>Syntax:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1495
				1496	<pre>
				1497	< <# elements> x <elementtype> >
				1498	</pre>
				1499
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1500	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1501	be any integer or floating point type.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1502
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1503	<h5>Examples:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1504
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1505	<table class="layout">
				1506	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1507	<td class="left"><tt><4 x i32></tt></td>
				1508	<td class="left">Vector of 4 32-bit integer values.</td>
				1509	</tr>
				1510	<tr class="layout">
				1511	<td class="left"><tt><8 x float></tt></td>
				1512	<td class="left">Vector of 8 32-bit floating-point values.</td>
				1513	</tr>
				1514	<tr class="layout">
				1515	<td class="left"><tt><2 x i64></tt></td>
				1516	<td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1517	</tr>
				1518	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1519	</div>
				1520
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1521	<!-- _______________________________________________________________________ -->
				1522	<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
				1523	<div class="doc_text">
				1524
				1525	<h5>Overview:</h5>
				1526
				1527	<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksen	8ac04ff	2007-10-14 00:34:53 +0000	[diff] [blame]	1528	corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1529	In LLVM, opaque types can eventually be resolved to any type (not just a
				1530	structure type).</p>
				1531
				1532	<h5>Syntax:</h5>
				1533
				1534	<pre>
				1535	opaque
				1536	</pre>
				1537
				1538	<h5>Examples:</h5>
				1539
				1540	<table class="layout">
				1541	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1542	<td class="left"><tt>opaque</tt></td>
				1543	<td class="left">An opaque type.</td>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1544	</tr>
				1545	</table>
				1546	</div>
				1547
				1548
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1549	<!-- *********************************************************************** -->
				1550	<div class="doc_section"> <a name="constants">Constants</a> </div>
				1551	<!-- *********************************************************************** -->
				1552
				1553	<div class="doc_text">
				1554
				1555	<p>LLVM has several different basic types of constants. This section describes
				1556	them all and their syntax.</p>
				1557
				1558	</div>
				1559
				1560	<!-- ======================================================================= -->
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1561	<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1562
				1563	<div class="doc_text">
				1564
				1565	<dl>
				1566	<dt><b>Boolean constants</b></dt>
				1567
				1568	<dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1569	constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1570	</dd>
				1571
				1572	<dt><b>Integer constants</b></dt>
				1573
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1574	<dd>Standard integers (such as '4') are constants of the <a
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1575	href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1576	integer types.
				1577	</dd>
				1578
				1579	<dt><b>Floating point constants</b></dt>
				1580
				1581	<dd>Floating point constants use standard decimal notation (e.g. 123.421),
				1582	exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	1583	notation (see below). The assembler requires the exact decimal value of
				1584	a floating-point constant. For example, the assembler accepts 1.25 but
				1585	rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
				1586	constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1587
				1588	<dt><b>Null pointer constants</b></dt>
				1589
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1590	<dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1591	and must be of <a href="#t_pointer">pointer type</a>.</dd>
				1592
				1593	</dl>
				1594
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1595	<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1596	of floating point constants. For example, the form '<tt>double
				1597	0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
				1598	4.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1599	(and the only time that they are generated by the disassembler) is when a
				1600	floating point constant must be emitted but it cannot be represented as a
				1601	decimal floating point number. For example, NaN's, infinities, and other
				1602	special values are represented in their IEEE hexadecimal format so that
				1603	assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1604
				1605	</div>
				1606
				1607	<!-- ======================================================================= -->
				1608	<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
				1609	</div>
				1610
				1611	<div class="doc_text">
Chris Lattner	d4f6b17	2005-03-07 22:13:59 +0000	[diff] [blame]	1612	<p>Aggregate constants arise from aggregation of simple constants
				1613	and smaller aggregate constants.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1614
				1615	<dl>
				1616	<dt><b>Structure constants</b></dt>
				1617
				1618	<dd>Structure constants are represented with notation similar to structure
				1619	type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner	64910ee	2007-12-25 20:34:52 +0000	[diff] [blame]	1620	(<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
				1621	where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>". Structure constants
Chris Lattner	d4f6b17	2005-03-07 22:13:59 +0000	[diff] [blame]	1622	must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1623	types of elements must match those specified by the type.
				1624	</dd>
				1625
				1626	<dt><b>Array constants</b></dt>
				1627
				1628	<dd>Array constants are represented with notation similar to array type
				1629	definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1630	(<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1631	constants must have <a href="#t_array">array type</a>, and the number and
				1632	types of elements must match those specified by the type.
				1633	</dd>
				1634
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1635	<dt><b>Vector constants</b></dt>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1636
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1637	<dd>Vector constants are represented with notation similar to vector type
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1638	definitions (a comma separated list of elements, surrounded by
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1639	less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1640	i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1641	href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1642	match those specified by the type.
				1643	</dd>
				1644
				1645	<dt><b>Zero initialization</b></dt>
				1646
				1647	<dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
				1648	value to zero of <em>any</em> type, including scalar and aggregate types.
				1649	This is often used to avoid having to print large zero initializers (e.g. for
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1650	large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1651	initializers.
				1652	</dd>
				1653	</dl>
				1654
				1655	</div>
				1656
				1657	<!-- ======================================================================= -->
				1658	<div class="doc_subsection">
				1659	<a name="globalconstants">Global Variable and Function Addresses</a>
				1660	</div>
				1661
				1662	<div class="doc_text">
				1663
				1664	<p>The addresses of <a href="#globalvars">global variables</a> and <a
				1665	href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1666	constants. These constants are explicitly referenced when the <a
				1667	href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1668	href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
				1669	file:</p>
				1670
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1671	<div class="doc_code">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1672	<pre>
Chris Lattner	a18a424	2007-06-06 18:28:13 +0000	[diff] [blame]	1673	@X = global i32 17
				1674	@Y = global i32 42
				1675	@Z = global [2 x i32] [ i32 @X, i32* @Y ]
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1676	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1677	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1678
				1679	</div>
				1680
				1681	<!-- ======================================================================= -->
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1682	<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1683	<div class="doc_text">
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1684	<p>The string '<tt>undef</tt>' is recognized as a type-less constant that has
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1685	no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1686	a constant is permitted.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1687
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1688	<p>Undefined values indicate to the compiler that the program is well defined
				1689	no matter what value is used, giving the compiler more freedom to optimize.
				1690	</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1691	</div>
				1692
				1693	<!-- ======================================================================= -->
				1694	<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
				1695	</div>
				1696
				1697	<div class="doc_text">
				1698
				1699	<p>Constant expressions are used to allow expressions involving other constants
				1700	to be used as constants. Constant expressions may be of any <a
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1701	href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1702	that does not have side effects (e.g. load and call are not supported). The
				1703	following is the syntax for constant expressions:</p>
				1704
				1705	<dl>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1706	<dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
				1707	<dd>Truncate a constant to another type. The bit size of CST must be larger
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1708	than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1709
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1710	<dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
				1711	<dd>Zero extend a constant to another type. The bit size of CST must be
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1712	smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1713
				1714	<dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
				1715	<dd>Sign extend a constant to another type. The bit size of CST must be
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1716	smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1717
				1718	<dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
				1719	<dd>Truncate a floating point constant to another floating point type. The
				1720	size of CST must be larger than the size of TYPE. Both types must be
				1721	floating point.</dd>
				1722
				1723	<dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
				1724	<dd>Floating point extend a constant to another type. The size of CST must be
				1725	smaller or equal to the size of TYPE. Both types must be floating point.</dd>
				1726
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	1727	<dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1728	<dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1729	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1730	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1731	of the same number of elements. If the value won't fit in the integer type,
				1732	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1733
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1734	<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1735	<dd>Convert a floating point constant to the corresponding signed integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1736	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1737	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1738	of the same number of elements. If the value won't fit in the integer type,
				1739	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1740
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1741	<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1742	<dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1743	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1744	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1745	of the same number of elements. If the value won't fit in the floating point
				1746	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1747
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1748	<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1749	<dd>Convert a signed integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1750	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1751	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1752	of the same number of elements. If the value won't fit in the floating point
				1753	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1754
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	1755	<dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
				1756	<dd>Convert a pointer typed constant to the corresponding integer constant
				1757	TYPE must be an integer type. CST must be of pointer type. The CST value is
				1758	zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
				1759
				1760	<dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
				1761	<dd>Convert a integer constant to a pointer constant. TYPE must be a
				1762	pointer type. CST must be of integer type. The CST value is zero extended,
				1763	truncated, or unchanged to make it fit in a pointer size. This one is
				1764	<i>really</i> dangerous!</dd>
				1765
				1766	<dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1767	<dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
				1768	identical (same number of bits). The conversion is done as if the CST value
				1769	was stored to memory and read back as TYPE. In other words, no bits change
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	1770	with this operator, just the type. This can be used for conversion of
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1771	vector types to any other type, as long as they have the same bit width. For
Dan Gohman	500233a	2008-09-08 16:45:59 +0000	[diff] [blame]	1772	pointers it is only valid to cast to another pointer type. It is not valid
				1773	to bitcast to or from an aggregate type.
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1774	</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1775
				1776	<dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
				1777
				1778	<dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
				1779	constants. As with the <a href="#i_getelementptr">getelementptr</a>
				1780	instruction, the index list may have zero or more indexes, which are required
				1781	to make sense for the type of "CSTPTR".</dd>
				1782
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	1783	<dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
				1784
				1785	<dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1786	constants.</dd>
				1787
				1788	<dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
				1789	<dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
				1790
				1791	<dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1792	<dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	1793
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	1794	<dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
				1795	<dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
				1796
				1797	<dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1798	<dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
				1799
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	1800	<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
				1801
				1802	<dd>Perform the <a href="#i_extractelement">extractelement
				1803	operation</a> on constants.
				1804
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	1805	<dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
				1806
				1807	<dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1808	operation</a> on constants.</dd>
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	1809
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	1810
				1811	<dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
				1812
				1813	<dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1814	operation</a> on constants.</dd>
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	1815
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1816	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				1817
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1818	<dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
				1819	be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1820	binary</a> operations. The constraints on operands are the same as those for
				1821	the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1822	values are allowed).</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1823	</dl>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1824	</div>
Chris Lattner	9ee5d22	2004-03-08 16:49:10 +0000	[diff] [blame]	1825
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1826	<!-- *********************************************************************** -->
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1827	<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
				1828	<!-- *********************************************************************** -->
				1829
				1830	<!-- ======================================================================= -->
				1831	<div class="doc_subsection">
				1832	<a name="inlineasm">Inline Assembler Expressions</a>
				1833	</div>
				1834
				1835	<div class="doc_text">
				1836
				1837	<p>
				1838	LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
				1839	Module-Level Inline Assembly</a>) through the use of a special value. This
				1840	value represents the inline assembler as a string (containing the instructions
				1841	to emit), a list of operand constraints (stored as a string), and a flag that
				1842	indicates whether or not the inline asm expression has side effects. An example
				1843	inline assembler expression is:
				1844	</p>
				1845
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1846	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1847	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1848	i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1849	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1850	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1851
				1852	<p>
				1853	Inline assembler expressions may <b>only</b> be used as the callee operand of
				1854	a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
				1855	</p>
				1856
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1857	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1858	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1859	%X = call i32 asm "<a href="#int_bswap">bswap</a> $0", "=r,r"(i32 %Y)
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1860	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1861	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1862
				1863	<p>
				1864	Inline asms with side effects not visible in the constraint list must be marked
				1865	as having side effects. This is done through the use of the
				1866	'<tt>sideeffect</tt>' keyword, like so:
				1867	</p>
				1868
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1869	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1870	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1871	call void asm sideeffect "eieio", ""()
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1872	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1873	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1874
				1875	<p>TODO: The format of the asm and constraints string still need to be
				1876	documented here. Constraints on what can be done (e.g. duplication, moving, etc
Chris Lattner	4f99335	2008-10-04 18:36:02 +0000	[diff] [blame]	1877	need to be documented). This is probably best done by reference to another
				1878	document that covers inline asm from a holistic perspective.
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1879	</p>
				1880
				1881	</div>
				1882
				1883	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1884	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				1885	<!-- *********************************************************************** -->
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1886
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1887	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1888
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1889	<p>The LLVM instruction set consists of several different
				1890	classifications of instructions: <a href="#terminators">terminator
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1891	instructions</a>, <a href="#binaryops">binary instructions</a>,
				1892	<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1893	href="#memoryops">memory instructions</a>, and <a href="#otherops">other
				1894	instructions</a>.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1895
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1896	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1897
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1898	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1899	<div class="doc_subsection"> <a name="terminators">Terminator
				1900	Instructions</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1901
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1902	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1903
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1904	<p>As mentioned <a href="#functionstructure">previously</a>, every
				1905	basic block in a program ends with a "Terminator" instruction, which
				1906	indicates which block should be executed after the current block is
				1907	finished. These terminator instructions typically yield a '<tt>void</tt>'
				1908	value: they produce control flow, not values (the one exception being
				1909	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1910	<p>There are six different terminator instructions: the '<a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1911	href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
				1912	instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	1913	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
				1914	href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
				1915	href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1916
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1917	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1918
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1919	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1920	<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
				1921	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1922	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1923	<h5>Syntax:</h5>
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	1924	<pre>
				1925	ret <type> <value> <i>; Return a value from a non-void function</i>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1926	ret void <i>; Return from void function</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1927	</pre>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1928
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1929	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1930
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	1931	<p>The '<tt>ret</tt>' instruction is used to return control flow (and
				1932	optionally a value) from a function back to the caller.</p>
John Criswell	4457dc9	2004-04-09 16:48:45 +0000	[diff] [blame]	1933	<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	1934	returns a value and then causes control flow, and one that just causes
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1935	control flow to occur.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1936
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1937	<h5>Arguments:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1938
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	1939	<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
				1940	the return value. The type of the return value must be a
				1941	'<a href="#t_firstclass">first class</a>' type.</p>
				1942
				1943	<p>A function is not <a href="#wellformed">well formed</a> if
				1944	it it has a non-void return type and contains a '<tt>ret</tt>'
				1945	instruction with no return value or a return value with a type that
				1946	does not match its type, or if it has a void return type and contains
				1947	a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1948
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1949	<h5>Semantics:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1950
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1951	<p>When the '<tt>ret</tt>' instruction is executed, control flow
				1952	returns back to the calling function's context. If the caller is a "<a
John Criswell	fa08187	2004-06-25 15:16:57 +0000	[diff] [blame]	1953	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1954	the instruction after the call. If the caller was an "<a
				1955	href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1956	at the beginning of the "normal" destination block. If the instruction
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1957	returns a value, that value shall set the call or invoke instruction's
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	1958	return value.
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1959
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1960	<h5>Example:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1961
				1962	<pre>
				1963	ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1964	ret void <i>; Return from a void function</i>
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	1965	ret { i32, i8 } { i32 4, i8 2 } <i>; Return an aggregate of values 4 and 2</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1966	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1967	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1968	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1969	<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1970	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1971	<h5>Syntax:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1972	<pre> br i1 <cond>, label <iftrue>, label <iffalse><br> br label <dest> <i>; Unconditional branch</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1973	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1974	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1975	<p>The '<tt>br</tt>' instruction is used to cause control flow to
				1976	transfer to a different basic block in the current function. There are
				1977	two forms of this instruction, corresponding to a conditional branch
				1978	and an unconditional branch.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1979	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1980	<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1981	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1982	unconditional form of the '<tt>br</tt>' instruction takes a single
				1983	'<tt>label</tt>' value as a target.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1984	<h5>Semantics:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1985	<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1986	argument is evaluated. If the value is <tt>true</tt>, control flows
				1987	to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
				1988	control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1989	<h5>Example:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1990	<pre>Test:<br> %cond = <a href="#i_icmp">icmp</a> eq, i32 %a, %b<br> br i1 %cond, label %IfEqual, label %IfUnequal<br>IfEqual:<br> <a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1991	href="#i_ret">ret</a> i32 1<br>IfUnequal:<br> <a href="#i_ret">ret</a> i32 0<br></pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1992	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1993	<!-- _______________________________________________________________________ -->
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1994	<div class="doc_subsubsection">
				1995	<a name="i_switch">'<tt>switch</tt>' Instruction</a>
				1996	</div>
				1997
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1998	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1999	<h5>Syntax:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2000
				2001	<pre>
				2002	switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
				2003	</pre>
				2004
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2005	<h5>Overview:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2006
				2007	<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
				2008	several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2009	instruction, allowing a branch to occur to one of many possible
				2010	destinations.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2011
				2012
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2013	<h5>Arguments:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2014
				2015	<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
				2016	comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
				2017	an array of pairs of comparison value constants and '<tt>label</tt>'s. The
				2018	table is not allowed to contain duplicate constant entries.</p>
				2019
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2020	<h5>Semantics:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2021
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2022	<p>The <tt>switch</tt> instruction specifies a table of values and
				2023	destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	2024	table is searched for the given value. If the value is found, control flow is
				2025	transfered to the corresponding destination; otherwise, control flow is
				2026	transfered to the default destination.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2027
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2028	<h5>Implementation:</h5>
				2029
				2030	<p>Depending on properties of the target machine and the particular
				2031	<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	2032	ways. For example, it could be generated as a series of chained conditional
				2033	branches or with a lookup table.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2034
				2035	<h5>Example:</h5>
				2036
				2037	<pre>
				2038	<i>; Emulate a conditional br instruction</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2039	%Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2040	switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2041
				2042	<i>; Emulate an unconditional br instruction</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2043	switch i32 0, label %dest [ ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2044
				2045	<i>; Implement a jump table:</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2046	switch i32 %val, label %otherwise [ i32 0, label %onzero
				2047	i32 1, label %onone
				2048	i32 2, label %ontwo ]
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2049	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2050	</div>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2051
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2052	<!-- _______________________________________________________________________ -->
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2053	<div class="doc_subsubsection">
				2054	<a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
				2055	</div>
				2056
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2057	<div class="doc_text">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2058
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2059	<h5>Syntax:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2060
				2061	<pre>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	2062	<result> = invoke [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] <ptr to function ty> <function ptr val>(<function args>) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner	76b8a33	2006-05-14 18:23:06 +0000	[diff] [blame]	2063	to label <normal label> unwind label <exception label>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2064	</pre>
				2065
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	2066	<h5>Overview:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2067
				2068	<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
				2069	function, with the possibility of control flow transfer to either the
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2070	'<tt>normal</tt>' label or the
				2071	'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2072	"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
				2073	"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2074	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2075	continued at the dynamically nearest "exception" label.
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2076
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2077	<h5>Arguments:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2078
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2079	<p>This instruction requires several arguments:</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2080
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2081	<ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2082	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	2083	The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2084	convention</a> the call should use. If none is specified, the call defaults
				2085	to using C calling conventions.
				2086	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	2087
				2088	<li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				2089	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				2090	and '<tt>inreg</tt>' attributes are valid here.</li>
				2091
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2092	<li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
				2093	function value being invoked. In most cases, this is a direct function
				2094	invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
				2095	an arbitrary pointer to function value.
				2096	</li>
				2097
				2098	<li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
				2099	function to be invoked. </li>
				2100
				2101	<li>'<tt>function args</tt>': argument list whose types match the function
				2102	signature argument types. If the function signature indicates the function
				2103	accepts a variable number of arguments, the extra arguments can be
				2104	specified. </li>
				2105
				2106	<li>'<tt>normal label</tt>': the label reached when the called function
				2107	executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
				2108
				2109	<li>'<tt>exception label</tt>': the label reached when a callee returns with
				2110	the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
				2111
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	2112	<li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	2113	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				2114	'<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2115	</ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2116
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2117	<h5>Semantics:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2118
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2119	<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2120	href="#i_call">call</a></tt>' instruction in most regards. The primary
				2121	difference is that it establishes an association with a label, which is used by
				2122	the runtime library to unwind the stack.</p>
				2123
				2124	<p>This instruction is used in languages with destructors to ensure that proper
				2125	cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
				2126	exception. Additionally, this is important for implementation of
				2127	'<tt>catch</tt>' clauses in high-level languages that support them.</p>
				2128
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2129	<h5>Example:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2130	<pre>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2131	%retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2132	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2133	%retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2134	unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2135	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2136	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2137
				2138
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2139	<!-- _______________________________________________________________________ -->
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2140
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2141	<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
				2142	Instruction</a> </div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2143
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2144	<div class="doc_text">
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2145
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2146	<h5>Syntax:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2147	<pre>
				2148	unwind
				2149	</pre>
				2150
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2151	<h5>Overview:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2152
				2153	<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
				2154	at the first callee in the dynamic call stack which used an <a
				2155	href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
				2156	primarily used to implement exception handling.</p>
				2157
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2158	<h5>Semantics:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2159
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	2160	<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2161	immediately halt. The dynamic call stack is then searched for the first <a
				2162	href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
				2163	execution continues at the "exceptional" destination block specified by the
				2164	<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
				2165	dynamic call chain, undefined behavior results.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2166	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2167
				2168	<!-- _______________________________________________________________________ -->
				2169
				2170	<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
				2171	Instruction</a> </div>
				2172
				2173	<div class="doc_text">
				2174
				2175	<h5>Syntax:</h5>
				2176	<pre>
				2177	unreachable
				2178	</pre>
				2179
				2180	<h5>Overview:</h5>
				2181
				2182	<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
				2183	instruction is used to inform the optimizer that a particular portion of the
				2184	code is not reachable. This can be used to indicate that the code after a
				2185	no-return function cannot be reached, and other facts.</p>
				2186
				2187	<h5>Semantics:</h5>
				2188
				2189	<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
				2190	</div>
				2191
				2192
				2193
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2194	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2195	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2196	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2197	<p>Binary operators are used to do most of the computation in a
Chris Lattner	5a15814	2008-04-01 18:47:32 +0000	[diff] [blame]	2198	program. They require two operands of the same type, execute an operation on them, and
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	2199	produce a single value. The operands might represent
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2200	multiple data, as is the case with the <a href="#t_vector">vector</a> data type.
Chris Lattner	5a15814	2008-04-01 18:47:32 +0000	[diff] [blame]	2201	The result value has the same type as its operands.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2202	<p>There are several different binary operators:</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2203	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2204	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2205	<div class="doc_subsubsection">
				2206	<a name="i_add">'<tt>add</tt>' Instruction</a>
				2207	</div>
				2208
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2209	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2210
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2211	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2212
				2213	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2214	<result> = add <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2215	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2216
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2217	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2218
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2219	<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2220
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2221	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2222
				2223	<p>The two arguments to the '<tt>add</tt>' instruction must be <a
				2224	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
				2225	<a href="#t_vector">vector</a> values. Both arguments must have identical
				2226	types.</p>
				2227
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2228	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2229
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2230	<p>The value produced is the integer or floating point sum of the two
				2231	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2232
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2233	<p>If an integer sum has unsigned overflow, the result returned is the
				2234	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2235	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2236
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2237	<p>Because LLVM integers use a two's complement representation, this
				2238	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2239
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2240	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2241
				2242	<pre>
				2243	<result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2244	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2245	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2246	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2247	<div class="doc_subsubsection">
				2248	<a name="i_sub">'<tt>sub</tt>' Instruction</a>
				2249	</div>
				2250
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2251	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2252
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2253	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2254
				2255	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2256	<result> = sub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2257	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2258
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2259	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2260
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2261	<p>The '<tt>sub</tt>' instruction returns the difference of its two
				2262	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2263
				2264	<p>Note that the '<tt>sub</tt>' instruction is used to represent the
				2265	'<tt>neg</tt>' instruction present in most other intermediate
				2266	representations.</p>
				2267
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2268	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2269
				2270	<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
				2271	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2272	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2273	types.</p>
				2274
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2275	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2276
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2277	<p>The value produced is the integer or floating point difference of
				2278	the two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2279
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2280	<p>If an integer difference has unsigned overflow, the result returned is the
				2281	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2282	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2283
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2284	<p>Because LLVM integers use a two's complement representation, this
				2285	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2286
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2287	<h5>Example:</h5>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	2288	<pre>
				2289	<result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2290	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2291	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2292	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2293
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2294	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2295	<div class="doc_subsubsection">
				2296	<a name="i_mul">'<tt>mul</tt>' Instruction</a>
				2297	</div>
				2298
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2299	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2300
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2301	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2302	<pre> <result> = mul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2303	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2304	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2305	<p>The '<tt>mul</tt>' instruction returns the product of its two
				2306	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2307
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2308	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2309
				2310	<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
				2311	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2312	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2313	types.</p>
				2314
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2315	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2316
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2317	<p>The value produced is the integer or floating point product of the
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2318	two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2319
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2320	<p>If the result of an integer multiplication has unsigned overflow,
				2321	the result returned is the mathematical result modulo
				2322	2<sup>n</sup>, where n is the bit width of the result.</p>
				2323	<p>Because LLVM integers use a two's complement representation, and the
				2324	result is the same width as the operands, this instruction returns the
				2325	correct result for both signed and unsigned integers. If a full product
				2326	(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
				2327	should be sign-extended or zero-extended as appropriate to the
				2328	width of the full product.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2329	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2330	<pre> <result> = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2331	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2332	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2333
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2334	<!-- _______________________________________________________________________ -->
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2335	<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
				2336	</a></div>
				2337	<div class="doc_text">
				2338	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2339	<pre> <result> = udiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2340	</pre>
				2341	<h5>Overview:</h5>
				2342	<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
				2343	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2344
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2345	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2346
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2347	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2348	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2349	values. Both arguments must have identical types.</p>
				2350
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2351	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2352
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2353	<p>The value produced is the unsigned integer quotient of the two operands.</p>
				2354	<p>Note that unsigned integer division and signed integer division are distinct
				2355	operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
				2356	<p>Division by zero leads to undefined behavior.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2357	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2358	<pre> <result> = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2359	</pre>
				2360	</div>
				2361	<!-- _______________________________________________________________________ -->
				2362	<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
				2363	</a> </div>
				2364	<div class="doc_text">
				2365	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2366	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2367	<result> = sdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2368	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2369
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2370	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2371
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2372	<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
				2373	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2374
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2375	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2376
				2377	<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
				2378	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2379	values. Both arguments must have identical types.</p>
				2380
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2381	<h5>Semantics:</h5>
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2382	<p>The value produced is the signed integer quotient of the two operands rounded towards zero.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2383	<p>Note that signed integer division and unsigned integer division are distinct
				2384	operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
				2385	<p>Division by zero leads to undefined behavior. Overflow also leads to
				2386	undefined behavior; this is a rare case, but can occur, for example,
				2387	by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2388	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2389	<pre> <result> = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2390	</pre>
				2391	</div>
				2392	<!-- _______________________________________________________________________ -->
				2393	<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2394	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2395	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2396	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2397	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2398	<result> = fdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2399	</pre>
				2400	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2401
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2402	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2403	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2404
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2405	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2406
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2407	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2408	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2409	of floating point values. Both arguments must have identical types.</p>
				2410
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2411	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2412
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2413	<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2414
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2415	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2416
				2417	<pre>
				2418	<result> = fdiv float 4.0, %var <i>; yields {float}:result = 4.0 / %var</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2419	</pre>
				2420	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2421
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2422	<!-- _______________________________________________________________________ -->
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2423	<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
				2424	</div>
				2425	<div class="doc_text">
				2426	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2427	<pre> <result> = urem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2428	</pre>
				2429	<h5>Overview:</h5>
				2430	<p>The '<tt>urem</tt>' instruction returns the remainder from the
				2431	unsigned division of its two arguments.</p>
				2432	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2433	<p>The two arguments to the '<tt>urem</tt>' instruction must be
				2434	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2435	values. Both arguments must have identical types.</p>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2436	<h5>Semantics:</h5>
				2437	<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2438	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2439	<p>Note that unsigned integer remainder and signed integer remainder are
				2440	distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
				2441	<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2442	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2443	<pre> <result> = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2444	</pre>
				2445
				2446	</div>
				2447	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2448	<div class="doc_subsubsection">
				2449	<a name="i_srem">'<tt>srem</tt>' Instruction</a>
				2450	</div>
				2451
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2452	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2453
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2454	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2455
				2456	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2457	<result> = srem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2458	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2459
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2460	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2461
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2462	<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	8017631	2007-11-05 23:35:22 +0000	[diff] [blame]	2463	signed division of its two operands. This instruction can also take
				2464	<a href="#t_vector">vector</a> versions of the values in which case
				2465	the elements must be integers.</p>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	2466
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2467	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2468
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2469	<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2470	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2471	values. Both arguments must have identical types.</p>
				2472
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2473	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2474
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2475	<p>This instruction returns the <i>remainder</i> of a division (where the result
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2476	has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
				2477	operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
Reid Spencer	c9fdfc8	2007-03-24 22:23:39 +0000	[diff] [blame]	2478	a value. For more information about the difference, see <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2479	href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencer	c9fdfc8	2007-03-24 22:23:39 +0000	[diff] [blame]	2480	Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencer	64f5c6c	2007-03-24 22:40:44 +0000	[diff] [blame]	2481	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer	c9fdfc8	2007-03-24 22:23:39 +0000	[diff] [blame]	2482	Wikipedia: modulo operation</a>.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2483	<p>Note that signed integer remainder and unsigned integer remainder are
				2484	distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
				2485	<p>Taking the remainder of a division by zero leads to undefined behavior.
				2486	Overflow also leads to undefined behavior; this is a rare case, but can occur,
				2487	for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
				2488	(The remainder doesn't actually overflow, but this rule lets srem be
				2489	implemented using instructions that return both the result of the division
				2490	and the remainder.)</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2491	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2492	<pre> <result> = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2493	</pre>
				2494
				2495	</div>
				2496	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2497	<div class="doc_subsubsection">
				2498	<a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
				2499
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2500	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2501
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2502	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2503	<pre> <result> = frem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2504	</pre>
				2505	<h5>Overview:</h5>
				2506	<p>The '<tt>frem</tt>' instruction returns the remainder from the
				2507	division of its two operands.</p>
				2508	<h5>Arguments:</h5>
				2509	<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2510	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2511	of floating point values. Both arguments must have identical types.</p>
				2512
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2513	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2514
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2515	<p>This instruction returns the <i>remainder</i> of a division.
				2516	The remainder has the same sign as the dividend.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2517
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2518	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2519
				2520	<pre>
				2521	<result> = frem float 4.0, %var <i>; yields {float}:result = 4.0 % %var</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2522	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2523	</div>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	2524
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2525	<!-- ======================================================================= -->
				2526	<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
				2527	Operations</a> </div>
				2528	<div class="doc_text">
				2529	<p>Bitwise binary operators are used to do various forms of
				2530	bit-twiddling in a program. They are generally very efficient
				2531	instructions and can commonly be strength reduced from other
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2532	instructions. They require two operands of the same type, execute an operation on them,
				2533	and produce a single value. The resulting value is the same type as its operands.</p>
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2534	</div>
				2535
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2536	<!-- _______________________________________________________________________ -->
				2537	<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
				2538	Instruction</a> </div>
				2539	<div class="doc_text">
				2540	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2541	<pre> <result> = shl <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2542	</pre>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2543
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2544	<h5>Overview:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2545
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2546	<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
				2547	the left a specified number of bits.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2548
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2549	<h5>Arguments:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2550
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2551	<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
Nate Begeman	5bc1ea0	2008-07-29 15:49:41 +0000	[diff] [blame]	2552	href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2553	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2554
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2555	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2556
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2557	<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
				2558	where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or
				2559	equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2560
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2561	<h5>Example:</h5><pre>
				2562	<result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
				2563	<result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
				2564	<result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2565	<result> = shl i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2566	</pre>
				2567	</div>
				2568	<!-- _______________________________________________________________________ -->
				2569	<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
				2570	Instruction</a> </div>
				2571	<div class="doc_text">
				2572	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2573	<pre> <result> = lshr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2574	</pre>
				2575
				2576	<h5>Overview:</h5>
				2577	<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2578	operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2579
				2580	<h5>Arguments:</h5>
				2581	<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Nate Begeman	5bc1ea0	2008-07-29 15:49:41 +0000	[diff] [blame]	2582	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2583	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2584
				2585	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2586
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2587	<p>This instruction always performs a logical shift right operation. The most
				2588	significant bits of the result will be filled with zero bits after the
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2589	shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
				2590	the number of bits in <tt>op1</tt>, the result is undefined.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2591
				2592	<h5>Example:</h5>
				2593	<pre>
				2594	<result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2595	<result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2596	<result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2597	<result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2598	<result> = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2599	</pre>
				2600	</div>
				2601
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2602	<!-- _______________________________________________________________________ -->
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2603	<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
				2604	Instruction</a> </div>
				2605	<div class="doc_text">
				2606
				2607	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2608	<pre> <result> = ashr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2609	</pre>
				2610
				2611	<h5>Overview:</h5>
				2612	<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2613	operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2614
				2615	<h5>Arguments:</h5>
				2616	<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Nate Begeman	5bc1ea0	2008-07-29 15:49:41 +0000	[diff] [blame]	2617	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2618	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2619
				2620	<h5>Semantics:</h5>
				2621	<p>This instruction always performs an arithmetic shift right operation,
				2622	The most significant bits of the result will be filled with the sign bit
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2623	of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
				2624	larger than the number of bits in <tt>op1</tt>, the result is undefined.
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2625	</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2626
				2627	<h5>Example:</h5>
				2628	<pre>
				2629	<result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2630	<result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2631	<result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2632	<result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2633	<result> = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2634	</pre>
				2635	</div>
				2636
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2637	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2638	<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
				2639	Instruction</a> </div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2640
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2641	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2642
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2643	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2644
				2645	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2646	<result> = and <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2647	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2648
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2649	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2650
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2651	<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
				2652	its two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2653
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2654	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2655
				2656	<p>The two arguments to the '<tt>and</tt>' instruction must be
				2657	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2658	values. Both arguments must have identical types.</p>
				2659
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2660	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2661	<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2662	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	2663	<div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2664	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2665	<tbody>
				2666	<tr>
				2667	<td>In0</td>
				2668	<td>In1</td>
				2669	<td>Out</td>
				2670	</tr>
				2671	<tr>
				2672	<td>0</td>
				2673	<td>0</td>
				2674	<td>0</td>
				2675	</tr>
				2676	<tr>
				2677	<td>0</td>
				2678	<td>1</td>
				2679	<td>0</td>
				2680	</tr>
				2681	<tr>
				2682	<td>1</td>
				2683	<td>0</td>
				2684	<td>0</td>
				2685	</tr>
				2686	<tr>
				2687	<td>1</td>
				2688	<td>1</td>
				2689	<td>1</td>
				2690	</tr>
				2691	</tbody>
				2692	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2693	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2694	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2695	<pre>
				2696	<result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2697	<result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
				2698	<result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2699	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2700	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2701	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2702	<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2703	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2704	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2705	<pre> <result> = or <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2706	</pre>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2707	<h5>Overview:</h5>
				2708	<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
				2709	or of its two operands.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2710	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2711
				2712	<p>The two arguments to the '<tt>or</tt>' instruction must be
				2713	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2714	values. Both arguments must have identical types.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2715	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2716	<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2717	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	2718	<div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2719	<table border="1" cellspacing="0" cellpadding="4">
				2720	<tbody>
				2721	<tr>
				2722	<td>In0</td>
				2723	<td>In1</td>
				2724	<td>Out</td>
				2725	</tr>
				2726	<tr>
				2727	<td>0</td>
				2728	<td>0</td>
				2729	<td>0</td>
				2730	</tr>
				2731	<tr>
				2732	<td>0</td>
				2733	<td>1</td>
				2734	<td>1</td>
				2735	</tr>
				2736	<tr>
				2737	<td>1</td>
				2738	<td>0</td>
				2739	<td>1</td>
				2740	</tr>
				2741	<tr>
				2742	<td>1</td>
				2743	<td>1</td>
				2744	<td>1</td>
				2745	</tr>
				2746	</tbody>
				2747	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2748	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2749	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2750	<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 \| %var</i>
				2751	<result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
				2752	<result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2753	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2754	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2755	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2756	<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
				2757	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2758	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2759	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2760	<pre> <result> = xor <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2761	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2762	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2763	<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
				2764	or of its two operands. The <tt>xor</tt> is used to implement the
				2765	"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2766	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2767	<p>The two arguments to the '<tt>xor</tt>' instruction must be
				2768	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2769	values. Both arguments must have identical types.</p>
				2770
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2771	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2772
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2773	<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2774	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	2775	<div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2776	<table border="1" cellspacing="0" cellpadding="4">
				2777	<tbody>
				2778	<tr>
				2779	<td>In0</td>
				2780	<td>In1</td>
				2781	<td>Out</td>
				2782	</tr>
				2783	<tr>
				2784	<td>0</td>
				2785	<td>0</td>
				2786	<td>0</td>
				2787	</tr>
				2788	<tr>
				2789	<td>0</td>
				2790	<td>1</td>
				2791	<td>1</td>
				2792	</tr>
				2793	<tr>
				2794	<td>1</td>
				2795	<td>0</td>
				2796	<td>1</td>
				2797	</tr>
				2798	<tr>
				2799	<td>1</td>
				2800	<td>1</td>
				2801	<td>0</td>
				2802	</tr>
				2803	</tbody>
				2804	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2805	</div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2806	<p> </p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2807	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2808	<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
				2809	<result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
				2810	<result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
				2811	<result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2812	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2813	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2814
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2815	<!-- ======================================================================= -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2816	<div class="doc_subsection">
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2817	<a name="vectorops">Vector Operations</a>
				2818	</div>
				2819
				2820	<div class="doc_text">
				2821
				2822	<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2823	target-independent manner. These instructions cover the element-access and
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2824	vector-specific operations needed to process vectors effectively. While LLVM
				2825	does directly support these vector operations, many sophisticated algorithms
				2826	will want to use target-specific intrinsics to take full advantage of a specific
				2827	target.</p>
				2828
				2829	</div>
				2830
				2831	<!-- _______________________________________________________________________ -->
				2832	<div class="doc_subsubsection">
				2833	<a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
				2834	</div>
				2835
				2836	<div class="doc_text">
				2837
				2838	<h5>Syntax:</h5>
				2839
				2840	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2841	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2842	</pre>
				2843
				2844	<h5>Overview:</h5>
				2845
				2846	<p>
				2847	The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2848	element from a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2849	</p>
				2850
				2851
				2852	<h5>Arguments:</h5>
				2853
				2854	<p>
				2855	The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2856	value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2857	an index indicating the position from which to extract the element.
				2858	The index may be a variable.</p>
				2859
				2860	<h5>Semantics:</h5>
				2861
				2862	<p>
				2863	The result is a scalar of the same type as the element type of
				2864	<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
				2865	<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
				2866	results are undefined.
				2867	</p>
				2868
				2869	<h5>Example:</h5>
				2870
				2871	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2872	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2873	</pre>
				2874	</div>
				2875
				2876
				2877	<!-- _______________________________________________________________________ -->
				2878	<div class="doc_subsubsection">
				2879	<a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
				2880	</div>
				2881
				2882	<div class="doc_text">
				2883
				2884	<h5>Syntax:</h5>
				2885
				2886	<pre>
Dan Gohman	f3480b9	2008-05-12 23:38:42 +0000	[diff] [blame]	2887	<result> = insertelement <n x <ty>> <val>, <ty> <elt>, i32 <idx> <i>; yields <n x <ty>></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2888	</pre>
				2889
				2890	<h5>Overview:</h5>
				2891
				2892	<p>
				2893	The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2894	element into a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2895	</p>
				2896
				2897
				2898	<h5>Arguments:</h5>
				2899
				2900	<p>
				2901	The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2902	value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2903	scalar value whose type must equal the element type of the first
				2904	operand. The third operand is an index indicating the position at
				2905	which to insert the value. The index may be a variable.</p>
				2906
				2907	<h5>Semantics:</h5>
				2908
				2909	<p>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2910	The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2911	element values are those of <tt>val</tt> except at position
				2912	<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
				2913	exceeds the length of <tt>val</tt>, the results are undefined.
				2914	</p>
				2915
				2916	<h5>Example:</h5>
				2917
				2918	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2919	%result = insertelement <4 x i32> %vec, i32 1, i32 0 <i>; yields <4 x i32></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2920	</pre>
				2921	</div>
				2922
				2923	<!-- _______________________________________________________________________ -->
				2924	<div class="doc_subsubsection">
				2925	<a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
				2926	</div>
				2927
				2928	<div class="doc_text">
				2929
				2930	<h5>Syntax:</h5>
				2931
				2932	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2933	<result> = shufflevector <n x <ty>> <v1>, <n x <ty>> <v2>, <n x i32> <mask> <i>; yields <n x <ty>></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2934	</pre>
				2935
				2936	<h5>Overview:</h5>
				2937
				2938	<p>
				2939	The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
				2940	from two input vectors, returning a vector of the same type.
				2941	</p>
				2942
				2943	<h5>Arguments:</h5>
				2944
				2945	<p>
				2946	The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
				2947	with types that match each other and types that match the result of the
				2948	instruction. The third argument is a shuffle mask, which has the same number
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2949	of elements as the other vector type, but whose element type is always 'i32'.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2950	</p>
				2951
				2952	<p>
				2953	The shuffle mask operand is required to be a constant vector with either
				2954	constant integer or undef values.
				2955	</p>
				2956
				2957	<h5>Semantics:</h5>
				2958
				2959	<p>
				2960	The elements of the two input vectors are numbered from left to right across
				2961	both of the vectors. The shuffle mask operand specifies, for each element of
				2962	the result vector, which element of the two input registers the result element
				2963	gets. The element selector may be undef (meaning "don't care") and the second
				2964	operand may be undef if performing a shuffle from only one vector.
				2965	</p>
				2966
				2967	<h5>Example:</h5>
				2968
				2969	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2970	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2971	<4 x i32> <i32 0, i32 4, i32 1, i32 5> <i>; yields <4 x i32></i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2972	%result = shufflevector <4 x i32> %v1, <4 x i32> undef,
				2973	<4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i> - Identity shuffle.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2974	</pre>
				2975	</div>
				2976
Tanya Lattner	0947429	2006-04-14 19:24:33 +0000	[diff] [blame]	2977
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2978	<!-- ======================================================================= -->
				2979	<div class="doc_subsection">
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2980	<a name="aggregateops">Aggregate Operations</a>
				2981	</div>
				2982
				2983	<div class="doc_text">
				2984
				2985	<p>LLVM supports several instructions for working with aggregate values.
				2986	</p>
				2987
				2988	</div>
				2989
				2990	<!-- _______________________________________________________________________ -->
				2991	<div class="doc_subsubsection">
				2992	<a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
				2993	</div>
				2994
				2995	<div class="doc_text">
				2996
				2997	<h5>Syntax:</h5>
				2998
				2999	<pre>
				3000	<result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
				3001	</pre>
				3002
				3003	<h5>Overview:</h5>
				3004
				3005	<p>
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3006	The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
				3007	or array element from an aggregate value.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3008	</p>
				3009
				3010
				3011	<h5>Arguments:</h5>
				3012
				3013	<p>
				3014	The first operand of an '<tt>extractvalue</tt>' instruction is a
				3015	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a>
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3016	type. The operands are constant indices to specify which value to extract
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3017	in a similar manner as indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3018	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3019	</p>
				3020
				3021	<h5>Semantics:</h5>
				3022
				3023	<p>
				3024	The result is the value at the position in the aggregate specified by
				3025	the index operands.
				3026	</p>
				3027
				3028	<h5>Example:</h5>
				3029
				3030	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3031	%result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3032	</pre>
				3033	</div>
				3034
				3035
				3036	<!-- _______________________________________________________________________ -->
				3037	<div class="doc_subsubsection">
				3038	<a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
				3039	</div>
				3040
				3041	<div class="doc_text">
				3042
				3043	<h5>Syntax:</h5>
				3044
				3045	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3046	<result> = insertvalue <aggregate type> <val>, <ty> <val>, <idx> <i>; yields <n x <ty>></i>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3047	</pre>
				3048
				3049	<h5>Overview:</h5>
				3050
				3051	<p>
				3052	The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3053	into a struct field or array element in an aggregate.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3054	</p>
				3055
				3056
				3057	<h5>Arguments:</h5>
				3058
				3059	<p>
				3060	The first operand of an '<tt>insertvalue</tt>' instruction is a
				3061	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
				3062	The second operand is a first-class value to insert.
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	3063	The following operands are constant indices
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3064	indicating the position at which to insert the value in a similar manner as
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3065	indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3066	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3067	The value to insert must have the same type as the value identified
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3068	by the indices.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3069
				3070	<h5>Semantics:</h5>
				3071
				3072	<p>
				3073	The result is an aggregate of the same type as <tt>val</tt>. Its
				3074	value is that of <tt>val</tt> except that the value at the position
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3075	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3076	</p>
				3077
				3078	<h5>Example:</h5>
				3079
				3080	<pre>
Dan Gohman	52bb2db	2008-06-23 15:26:37 +0000	[diff] [blame]	3081	%result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3082	</pre>
				3083	</div>
				3084
				3085
				3086	<!-- ======================================================================= -->
				3087	<div class="doc_subsection">
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3088	<a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3089	</div>
				3090
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3091	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3092
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3093	<p>A key design point of an SSA-based representation is how it
				3094	represents memory. In LLVM, no memory locations are in SSA form, which
				3095	makes things very simple. This section describes how to read, write,
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3096	allocate, and free memory in LLVM.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3097
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3098	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3099
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3100	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3101	<div class="doc_subsubsection">
				3102	<a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
				3103	</div>
				3104
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3105	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3106
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3107	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3108
				3109	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3110	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3111	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3112
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3113	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3114
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3115	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3116	heap and returns a pointer to it. The object is always allocated in the generic
				3117	address space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3118
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3119	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3120
				3121	<p>The '<tt>malloc</tt>' instruction allocates
				3122	<tt>sizeof(<type>)*NumElements</tt>
John Criswell	6e4ca61	2004-02-24 16:13:56 +0000	[diff] [blame]	3123	bytes of memory from the operating system and returns a pointer of the
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3124	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3125	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3126	If a constant alignment is specified, the value result of the allocation is guaranteed to
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3127	be aligned to at least that boundary. If not specified, or if zero, the target can
				3128	choose to align the allocation on any convenient boundary.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3129
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3130	<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3131
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3132	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3133
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3134	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	3135	a pointer is returned. The result of a zero byte allocattion is undefined. The
				3136	result is null if there is insufficient memory available.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3137
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3138	<h5>Example:</h5>
				3139
				3140	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3141	%array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3142
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	3143	%size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
				3144	%array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
				3145	%array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
				3146	%array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
				3147	%array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3148	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3149	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3150
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3151	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3152	<div class="doc_subsubsection">
				3153	<a name="i_free">'<tt>free</tt>' Instruction</a>
				3154	</div>
				3155
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3156	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3157
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3158	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3159
				3160	<pre>
				3161	free <type> <value> <i>; yields {void}</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3162	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3163
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3164	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3165
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3166	<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3167	memory heap to be reallocated in the future.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3168
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3169	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3170
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3171	<p>'<tt>value</tt>' shall be a pointer value that points to a value
				3172	that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
				3173	instruction.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3174
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3175	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3176
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3177	<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattner	e0db56d	2008-04-19 22:41:32 +0000	[diff] [blame]	3178	after this instruction executes. If the pointer is null, the operation
				3179	is a noop.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3180
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3181	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3182
				3183	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3184	%array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
				3185	free [4 x i8]* %array
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3186	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3187	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3188
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3189	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3190	<div class="doc_subsubsection">
				3191	<a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
				3192	</div>
				3193
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3194	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3195
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3196	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3197
				3198	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3199	<result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3200	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3201
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3202	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3203
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3204	<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
				3205	currently executing function, to be automatically released when this function
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3206	returns to its caller. The object is always allocated in the generic address
				3207	space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3208
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3209	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3210
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3211	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3212	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3213	appropriate type to the program. If "NumElements" is specified, it is the
				3214	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3215	If a constant alignment is specified, the value result of the allocation is guaranteed
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3216	to be aligned to at least that boundary. If not specified, or if zero, the target
				3217	can choose to align the allocation on any convenient boundary.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3218
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3219	<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3220
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3221	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3222
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	3223	<p>Memory is allocated; a pointer is returned. The operation is undefiend if
				3224	there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3225	memory is automatically released when the function returns. The '<tt>alloca</tt>'
				3226	instruction is commonly used to represent automatic variables that must
				3227	have an address available. When the function returns (either with the <tt><a
John Criswell	dae2e93	2005-05-12 16:55:34 +0000	[diff] [blame]	3228	href="#i_ret">ret</a></tt> or <tt><a href="#i_unwind">unwind</a></tt>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3229	instructions), the memory is reclaimed. Allocating zero bytes
				3230	is legal, but the result is undefined.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3231
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3232	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3233
				3234	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3235	%ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3236	%ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
				3237	%ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3238	%ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3239	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3240	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3241
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3242	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3243	<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
				3244	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3245	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3246	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3247	<pre> <result> = load <ty>* <pointer>[, align <alignment>]<br> <result> = volatile load <ty>* <pointer>[, align <alignment>]<br></pre>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3248	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3249	<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3250	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3251	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	3252	address from which to load. The pointer must point to a <a
Chris Lattner	e53e508	2004-06-03 22:57:15 +0000	[diff] [blame]	3253	href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	3254	marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3255	the number or order of execution of this <tt>load</tt> with other
				3256	volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
				3257	instructions. </p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3258	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3259	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3260	(that is, the alignment of the memory address). A value of 0 or an
				3261	omitted "align" argument means that the operation has the preferential
				3262	alignment for the target. It is the responsibility of the code emitter
				3263	to ensure that the alignment information is correct. Overestimating
				3264	the alignment results in an undefined behavior. Underestimating the
				3265	alignment may produce less efficient code. An alignment of 1 is always
				3266	safe.
				3267	</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3268	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3269	<p>The location of memory pointed to is loaded.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3270	<h5>Examples:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3271	<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3272	<a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3273	href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
				3274	%val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3275	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3276	</div>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3277	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3278	<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
				3279	Instruction</a> </div>
Reid Spencer	035ab57	2006-11-09 21:18:01 +0000	[diff] [blame]	3280	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3281	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3282	<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3283	volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3284	</pre>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3285	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3286	<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3287	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3288	<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3289	to store and an address at which to store it. The type of the '<tt><pointer></tt>'
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3290	operand must be a pointer to the <a href="#t_firstclass">first class</a> type
				3291	of the '<tt><value></tt>'
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3292	operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3293	optimizer is not allowed to modify the number or order of execution of
				3294	this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
				3295	href="#i_store">store</a></tt> instructions.</p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3296	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3297	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3298	(that is, the alignment of the memory address). A value of 0 or an
				3299	omitted "align" argument means that the operation has the preferential
				3300	alignment for the target. It is the responsibility of the code emitter
				3301	to ensure that the alignment information is correct. Overestimating
				3302	the alignment results in an undefined behavior. Underestimating the
				3303	alignment may produce less efficient code. An alignment of 1 is always
				3304	safe.
				3305	</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3306	<h5>Semantics:</h5>
				3307	<p>The contents of memory are updated to contain '<tt><value></tt>'
				3308	at the location specified by the '<tt><pointer></tt>' operand.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3309	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3310	<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling	8c6c72d	2007-10-22 05:10:05 +0000	[diff] [blame]	3311	store i32 3, i32* %ptr <i>; yields {void}</i>
				3312	%val = <a href="#i_load">load</a> i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3313	</pre>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3314	</div>
				3315
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3316	<!-- _______________________________________________________________________ -->
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3317	<div class="doc_subsubsection">
				3318	<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
				3319	</div>
				3320
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3321	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3322	<h5>Syntax:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3323	<pre>
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3324	<result> = getelementptr <pty>* <ptrval>{, <ty> <idx>}*
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3325	</pre>
				3326
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3327	<h5>Overview:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3328
				3329	<p>
				3330	The '<tt>getelementptr</tt>' instruction is used to get the address of a
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3331	subelement of an aggregate data structure. It performs address calculation only
				3332	and does not access memory.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3333
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3334	<h5>Arguments:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3335
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3336	<p>The first argument is always a pointer, and forms the basis of the
				3337	calculation. The remaining arguments are indices, that indicate which of the
				3338	elements of the aggregate object are indexed. The interpretation of each index
				3339	is dependent on the type being indexed into. The first index always indexes the
				3340	pointer value given as the first argument, the second index indexes a value of
				3341	the type pointed to (not necessarily the value directly pointed to, since the
				3342	first index can be non-zero), etc. The first type indexed into must be a pointer
				3343	value, subsequent types can be arrays, vectors and structs. Note that subsequent
				3344	types being indexed into can never be pointers, since that would require loading
				3345	the pointer before continuing calculation.</p>
				3346
				3347	<p>The type of each index argument depends on the type it is indexing into.
				3348	When indexing into a (packed) structure, only <tt>i32</tt> integer
				3349	<b>constants</b> are allowed. When indexing into an array, pointer or vector,
				3350	only integers of 32 or 64 bits are allowed (also non-constants). 32-bit values
				3351	will be sign extended to 64-bits if required.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3352
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3353	<p>For example, let's consider a C code fragment and how it gets
				3354	compiled to LLVM:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3355
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3356	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3357	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3358	struct RT {
				3359	char A;
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3360	int B[10][20];
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3361	char C;
				3362	};
				3363	struct ST {
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3364	int X;
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3365	double Y;
				3366	struct RT Z;
				3367	};
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3368
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3369	int foo(struct ST s) {
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3370	return &s[1].Z.B[5][13];
				3371	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3372	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3373	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3374
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3375	<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3376
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3377	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3378	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3379	%RT = type { i8 , [10 x [20 x i32]], i8 }
				3380	%ST = type { i32, double, %RT }
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3381
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3382	define i32* %foo(%ST* %s) {
				3383	entry:
				3384	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3385	ret i32* %reg
				3386	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3387	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3388	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3389
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3390	<h5>Semantics:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3391
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3392	<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3393	type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3394	}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3395	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3396	i8 }</tt>' type, another structure. The third index indexes into the second
				3397	element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3398	array. The two dimensions of the array are subscripted into, yielding an
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3399	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3400	to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3401
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3402	<p>Note that it is perfectly legal to index partially through a
				3403	structure, returning a pointer to an inner element. Because of this,
				3404	the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3405
				3406	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3407	define i32* %foo(%ST* %s) {
				3408	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3409	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3410	%t3 = getelementptr %RT* %t2, i32 0, i32 1 <i>; yields [10 x [20 x i32]]*:%t3</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3411	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3412	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3413	ret i32* %t5
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3414	}
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3415	</pre>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3416
				3417	<p>Note that it is undefined to access an array out of bounds: array and
				3418	pointer indexes must always be within the defined bounds of the array type.
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	3419	The one exception for this rule is zero length arrays. These arrays are
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3420	defined to be accessible as variable length arrays, which requires access
				3421	beyond the zero'th element.</p>
				3422
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3423	<p>The getelementptr instruction is often confusing. For some more insight
				3424	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3425	FAQ</a>.</p>
				3426
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3427	<h5>Example:</h5>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3428
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3429	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3430	<i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3431	%aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
				3432	<i>; yields i8*:vptr</i>
				3433	%vptr = getelementptr {i32, <2 x i8>}* %svptr, i64 0, i32 1, i32 1
				3434	<i>; yields i8*:eptr</i>
				3435	%eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3436	</pre>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3437	</div>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3438
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3439	<!-- ======================================================================= -->
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3440	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3441	</div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3442	<div class="doc_text">
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3443	<p>The instructions in this category are the conversion instructions (casting)
				3444	which all take a single operand and a type. They perform various bit conversions
				3445	on the operand.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3446	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3447
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3448	<!-- _______________________________________________________________________ -->
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3449	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3450	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3451	</div>
				3452	<div class="doc_text">
				3453
				3454	<h5>Syntax:</h5>
				3455	<pre>
				3456	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3457	</pre>
				3458
				3459	<h5>Overview:</h5>
				3460	<p>
				3461	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3462	</p>
				3463
				3464	<h5>Arguments:</h5>
				3465	<p>
				3466	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3467	be an <a href="#t_integer">integer</a> type, and a type that specifies the size
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	3468	and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3469	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3470	<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3471
				3472	<h5>Semantics:</h5>
				3473	<p>
				3474	The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3475	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3476	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3477	It will always truncate bits.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3478
				3479	<h5>Example:</h5>
				3480	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3481	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3482	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3483	%Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3484	</pre>
				3485	</div>
				3486
				3487	<!-- _______________________________________________________________________ -->
				3488	<div class="doc_subsubsection">
				3489	<a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
				3490	</div>
				3491	<div class="doc_text">
				3492
				3493	<h5>Syntax:</h5>
				3494	<pre>
				3495	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3496	</pre>
				3497
				3498	<h5>Overview:</h5>
				3499	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3500	<tt>ty2</tt>.</p>
				3501
				3502
				3503	<h5>Arguments:</h5>
				3504	<p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	3505	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3506	also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3507	<tt>value</tt> must be smaller than the bit size of the destination type,
				3508	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3509
				3510	<h5>Semantics:</h5>
				3511	<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
Chris Lattner	d1d2517	2007-05-24 19:13:27 +0000	[diff] [blame]	3512	bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3513
Reid Spencer	b592952	2007-01-12 15:46:11 +0000	[diff] [blame]	3514	<p>When zero extending from i1, the result will always be either 0 or 1.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3515
				3516	<h5>Example:</h5>
				3517	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3518	%X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3519	%Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3520	</pre>
				3521	</div>
				3522
				3523	<!-- _______________________________________________________________________ -->
				3524	<div class="doc_subsubsection">
				3525	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3526	</div>
				3527	<div class="doc_text">
				3528
				3529	<h5>Syntax:</h5>
				3530	<pre>
				3531	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3532	</pre>
				3533
				3534	<h5>Overview:</h5>
				3535	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3536
				3537	<h5>Arguments:</h5>
				3538	<p>
				3539	The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	3540	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3541	also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3542	<tt>value</tt> must be smaller than the bit size of the destination type,
				3543	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3544
				3545	<h5>Semantics:</h5>
				3546	<p>
				3547	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3548	bit (highest order bit) of the <tt>value</tt> until it reaches the bit size of
Chris Lattner	d1d2517	2007-05-24 19:13:27 +0000	[diff] [blame]	3549	the type <tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3550
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3551	<p>When sign extending from i1, the extension always results in -1 or 0.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3552
				3553	<h5>Example:</h5>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3554	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3555	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3556	%Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3557	</pre>
				3558	</div>
				3559
				3560	<!-- _______________________________________________________________________ -->
				3561	<div class="doc_subsubsection">
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3562	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				3563	</div>
				3564
				3565	<div class="doc_text">
				3566
				3567	<h5>Syntax:</h5>
				3568
				3569	<pre>
				3570	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3571	</pre>
				3572
				3573	<h5>Overview:</h5>
				3574	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				3575	<tt>ty2</tt>.</p>
				3576
				3577
				3578	<h5>Arguments:</h5>
				3579	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				3580	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				3581	cast it to. The size of <tt>value</tt> must be larger than the size of
				3582	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				3583	<i>no-op cast</i>.</p>
				3584
				3585	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3586	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				3587	<a href="#t_floating">floating point</a> type to a smaller
				3588	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				3589	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3590
				3591	<h5>Example:</h5>
				3592	<pre>
				3593	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				3594	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				3595	</pre>
				3596	</div>
				3597
				3598	<!-- _______________________________________________________________________ -->
				3599	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3600	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				3601	</div>
				3602	<div class="doc_text">
				3603
				3604	<h5>Syntax:</h5>
				3605	<pre>
				3606	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				3607	</pre>
				3608
				3609	<h5>Overview:</h5>
				3610	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				3611	floating point value.</p>
				3612
				3613	<h5>Arguments:</h5>
				3614	<p>The '<tt>fpext</tt>' instruction takes a
				3615	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3616	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				3617	type must be smaller than the destination type.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3618
				3619	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3620	<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	3621	<a href="#t_floating">floating point</a> type to a larger
				3622	<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3623	used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3624	<tt>bitcast</tt> to make a <i>no-op cast</i> for a floating point cast.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3625
				3626	<h5>Example:</h5>
				3627	<pre>
				3628	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				3629	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				3630	</pre>
				3631	</div>
				3632
				3633	<!-- _______________________________________________________________________ -->
				3634	<div class="doc_subsubsection">
Reid Spencer	24d6da5	2007-01-21 00:29:26 +0000	[diff] [blame]	3635	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3636	</div>
				3637	<div class="doc_text">
				3638
				3639	<h5>Syntax:</h5>
				3640	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3641	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3642	</pre>
				3643
				3644	<h5>Overview:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3645	<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3646	unsigned integer equivalent of type <tt>ty2</tt>.
				3647	</p>
				3648
				3649	<h5>Arguments:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3650	<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	3651	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3652	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3653	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3654	vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3655
				3656	<h5>Semantics:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3657	<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3658	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3659	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				3660	the results are undefined.</p>
				3661
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3662	<h5>Example:</h5>
				3663	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3664	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	3665	%Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3666	%X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3667	</pre>
				3668	</div>
				3669
				3670	<!-- _______________________________________________________________________ -->
				3671	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3672	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3673	</div>
				3674	<div class="doc_text">
				3675
				3676	<h5>Syntax:</h5>
				3677	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3678	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3679	</pre>
				3680
				3681	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3682	<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3683	<a href="#t_floating">floating point</a> <tt>value</tt> to type <tt>ty2</tt>.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3684	</p>
				3685
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3686	<h5>Arguments:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3687	<p> The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	3688	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3689	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3690	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3691	vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3692
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3693	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3694	<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3695	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3696	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				3697	the results are undefined.</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3698
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	3699	<h5>Example:</h5>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3700	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3701	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	3702	%Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3703	%X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3704	</pre>
				3705	</div>
				3706
				3707	<!-- _______________________________________________________________________ -->
				3708	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3709	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3710	</div>
				3711	<div class="doc_text">
				3712
				3713	<h5>Syntax:</h5>
				3714	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3715	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3716	</pre>
				3717
				3718	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3719	<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3720	integer and converts that value to the <tt>ty2</tt> type.</p>
				3721
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3722	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	3723	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				3724	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3725	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3726	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3727	floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3728
				3729	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3730	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3731	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	3732	the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3733
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3734	<h5>Example:</h5>
				3735	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3736	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3737	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3738	</pre>
				3739	</div>
				3740
				3741	<!-- _______________________________________________________________________ -->
				3742	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3743	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3744	</div>
				3745	<div class="doc_text">
				3746
				3747	<h5>Syntax:</h5>
				3748	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3749	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3750	</pre>
				3751
				3752	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3753	<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3754	integer and converts that value to the <tt>ty2</tt> type.</p>
				3755
				3756	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	3757	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				3758	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3759	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3760	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3761	floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3762
				3763	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3764	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3765	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	3766	the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3767
				3768	<h5>Example:</h5>
				3769	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3770	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3771	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3772	</pre>
				3773	</div>
				3774
				3775	<!-- _______________________________________________________________________ -->
				3776	<div class="doc_subsubsection">
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3777	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				3778	</div>
				3779	<div class="doc_text">
				3780
				3781	<h5>Syntax:</h5>
				3782	<pre>
				3783	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				3784	</pre>
				3785
				3786	<h5>Overview:</h5>
				3787	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				3788	the integer type <tt>ty2</tt>.</p>
				3789
				3790	<h5>Arguments:</h5>
				3791	<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	3792	must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3793	<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
				3794
				3795	<h5>Semantics:</h5>
				3796	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				3797	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				3798	truncating or zero extending that value to the size of the integer type. If
				3799	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				3800	<tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3801	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				3802	change.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3803
				3804	<h5>Example:</h5>
				3805	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3806	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				3807	%Y = ptrtoint i32* %x to i64 <i>; yields zero extension on 32-bit architecture</i>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3808	</pre>
				3809	</div>
				3810
				3811	<!-- _______________________________________________________________________ -->
				3812	<div class="doc_subsubsection">
				3813	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				3814	</div>
				3815	<div class="doc_text">
				3816
				3817	<h5>Syntax:</h5>
				3818	<pre>
				3819	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				3820	</pre>
				3821
				3822	<h5>Overview:</h5>
				3823	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				3824	a pointer type, <tt>ty2</tt>.</p>
				3825
				3826	<h5>Arguments:</h5>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	3827	<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3828	value to cast, and a type to cast it to, which must be a
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	3829	<a href="#t_pointer">pointer</a> type.
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3830
				3831	<h5>Semantics:</h5>
				3832	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				3833	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				3834	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				3835	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				3836	the size of a pointer then a zero extension is done. If they are the same size,
				3837	nothing is done (<i>no-op cast</i>).</p>
				3838
				3839	<h5>Example:</h5>
				3840	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3841	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				3842	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				3843	%Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3844	</pre>
				3845	</div>
				3846
				3847	<!-- _______________________________________________________________________ -->
				3848	<div class="doc_subsubsection">
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3849	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3850	</div>
				3851	<div class="doc_text">
				3852
				3853	<h5>Syntax:</h5>
				3854	<pre>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3855	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3856	</pre>
				3857
				3858	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3859
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3860	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3861	<tt>ty2</tt> without changing any bits.</p>
				3862
				3863	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3864
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3865	<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Dan Gohman	500233a	2008-09-08 16:45:59 +0000	[diff] [blame]	3866	a non-aggregate first class value, and a type to cast it to, which must also be
				3867	a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
				3868	<tt>value</tt>
Reid Spencer	19b569f	2007-01-09 20:08:58 +0000	[diff] [blame]	3869	and the destination type, <tt>ty2</tt>, must be identical. If the source
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3870	type is a pointer, the destination type must also be a pointer. This
				3871	instruction supports bitwise conversion of vectors to integers and to vectors
				3872	of other types (as long as they have the same size).</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3873
				3874	<h5>Semantics:</h5>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3875	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3876	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				3877	this conversion. The conversion is done as if the <tt>value</tt> had been
				3878	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				3879	converted to other pointer types with this instruction. To convert pointers to
				3880	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				3881	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3882
				3883	<h5>Example:</h5>
				3884	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3885	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3886	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
				3887	%Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	3888	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3889	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3890
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3891	<!-- ======================================================================= -->
				3892	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				3893	<div class="doc_text">
				3894	<p>The instructions in this category are the "miscellaneous"
				3895	instructions, which defy better classification.</p>
				3896	</div>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3897
				3898	<!-- _______________________________________________________________________ -->
				3899	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				3900	</div>
				3901	<div class="doc_text">
				3902	<h5>Syntax:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3903	<pre> <result> = icmp <cond> <ty> <op1>, <op2> <i>; yields {i1} or {<N x i1&gt}:result</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3904	</pre>
				3905	<h5>Overview:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3906	<p>The '<tt>icmp</tt>' instruction returns a boolean value or
				3907	a vector of boolean values based on comparison
				3908	of its two integer, integer vector, or pointer operands.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3909	<h5>Arguments:</h5>
				3910	<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3911	the condition code indicating the kind of comparison to perform. It is not
				3912	a value, just a keyword. The possible condition code are:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3913	<ol>
				3914	<li><tt>eq</tt>: equal</li>
				3915	<li><tt>ne</tt>: not equal </li>
				3916	<li><tt>ugt</tt>: unsigned greater than</li>
				3917	<li><tt>uge</tt>: unsigned greater or equal</li>
				3918	<li><tt>ult</tt>: unsigned less than</li>
				3919	<li><tt>ule</tt>: unsigned less or equal</li>
				3920	<li><tt>sgt</tt>: signed greater than</li>
				3921	<li><tt>sge</tt>: signed greater or equal</li>
				3922	<li><tt>slt</tt>: signed less than</li>
				3923	<li><tt>sle</tt>: signed less or equal</li>
				3924	</ol>
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	3925	<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3926	<a href="#t_pointer">pointer</a>
				3927	or integer <a href="#t_vector">vector</a> typed.
				3928	They must also be identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3929	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3930	<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3931	the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3932	yields either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt> result, as follows:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3933	<ol>
				3934	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				3935	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				3936	</li>
				3937	<li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
				3938	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				3939	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3940	<tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3941	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3942	<tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3943	<li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3944	<tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3945	<li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3946	<tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3947	<li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3948	<tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3949	<li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3950	<tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3951	<li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3952	<tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3953	<li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3954	<tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3955	</ol>
				3956	<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3957	values are compared as if they were integers.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3958	<p>If the operands are integer vectors, then they are compared
				3959	element by element. The result is an <tt>i1</tt> vector with
				3960	the same number of elements as the values being compared.
				3961	Otherwise, the result is an <tt>i1</tt>.
				3962	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3963
				3964	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3965	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				3966	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				3967	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				3968	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				3969	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				3970	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3971	</pre>
				3972	</div>
				3973
				3974	<!-- _______________________________________________________________________ -->
				3975	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				3976	</div>
				3977	<div class="doc_text">
				3978	<h5>Syntax:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3979	<pre> <result> = fcmp <cond> <ty> <op1>, <op2> <i>; yields {i1} or {<N x i1&gt}:result</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3980	</pre>
				3981	<h5>Overview:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3982	<p>The '<tt>fcmp</tt>' instruction returns a boolean value
				3983	or vector of boolean values based on comparison
				3984	of its operands.
				3985	<p>
				3986	If the operands are floating point scalars, then the result
				3987	type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
				3988	</p>
				3989	<p>If the operands are floating point vectors, then the result type
				3990	is a vector of boolean with the same number of elements as the
				3991	operands being compared.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3992	<h5>Arguments:</h5>
				3993	<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3994	the condition code indicating the kind of comparison to perform. It is not
				3995	a value, just a keyword. The possible condition code are:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3996	<ol>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3997	<li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3998	<li><tt>oeq</tt>: ordered and equal</li>
				3999	<li><tt>ogt</tt>: ordered and greater than </li>
				4000	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4001	<li><tt>olt</tt>: ordered and less than </li>
				4002	<li><tt>ole</tt>: ordered and less than or equal</li>
				4003	<li><tt>one</tt>: ordered and not equal</li>
				4004	<li><tt>ord</tt>: ordered (no nans)</li>
				4005	<li><tt>ueq</tt>: unordered or equal</li>
				4006	<li><tt>ugt</tt>: unordered or greater than </li>
				4007	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4008	<li><tt>ult</tt>: unordered or less than </li>
				4009	<li><tt>ule</tt>: unordered or less than or equal</li>
				4010	<li><tt>une</tt>: unordered or not equal</li>
				4011	<li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4012	<li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4013	</ol>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4014	<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer	93a4985	2006-12-06 07:08:07 +0000	[diff] [blame]	4015	<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4016	<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
				4017	either a <a href="#t_floating">floating point</a> type
				4018	or a <a href="#t_vector">vector</a> of floating point type.
				4019	They must have identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4020	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4021	<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4022	according to the condition code given as <tt>cond</tt>.
				4023	If the operands are vectors, then the vectors are compared
				4024	element by element.
				4025	Each comparison performed
				4026	always yields an <a href="#t_primitive">i1</a> result, as follows:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4027	<ol>
				4028	<li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4029	<li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4030	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4031	<li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4032	<tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4033	<li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4034	<tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4035	<li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4036	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4037	<li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4038	<tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4039	<li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4040	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4041	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				4042	<li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4043	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4044	<li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4045	<tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4046	<li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4047	<tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4048	<li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4049	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4050	<li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4051	<tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4052	<li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4053	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4054	<li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4055	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				4056	</ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4057
				4058	<h5>Example:</h5>
				4059	<pre> <result> = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4060	<result> = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
				4061	<result> = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				4062	<result> = fcmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4063	</pre>
				4064	</div>
				4065
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4066	<!-- _______________________________________________________________________ -->
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4067	<div class="doc_subsubsection">
				4068	<a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
				4069	</div>
				4070	<div class="doc_text">
				4071	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4072	<pre> <result> = vicmp <cond> <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4073	</pre>
				4074	<h5>Overview:</h5>
				4075	<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
				4076	element-wise comparison of its two integer vector operands.</p>
				4077	<h5>Arguments:</h5>
				4078	<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
				4079	the condition code indicating the kind of comparison to perform. It is not
				4080	a value, just a keyword. The possible condition code are:
				4081	<ol>
				4082	<li><tt>eq</tt>: equal</li>
				4083	<li><tt>ne</tt>: not equal </li>
				4084	<li><tt>ugt</tt>: unsigned greater than</li>
				4085	<li><tt>uge</tt>: unsigned greater or equal</li>
				4086	<li><tt>ult</tt>: unsigned less than</li>
				4087	<li><tt>ule</tt>: unsigned less or equal</li>
				4088	<li><tt>sgt</tt>: signed greater than</li>
				4089	<li><tt>sge</tt>: signed greater or equal</li>
				4090	<li><tt>slt</tt>: signed less than</li>
				4091	<li><tt>sle</tt>: signed less or equal</li>
				4092	</ol>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4093	<p>The remaining two arguments must be <a href="#t_vector">vector</a> or
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4094	<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
				4095	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4096	<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4097	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4098	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
				4099	identical type as the values being compared. The most significant bit in each
				4100	element is 1 if the element-wise comparison evaluates to true, and is 0
				4101	otherwise. All other bits of the result are undefined. The condition codes
				4102	are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
				4103	instruction</a>.
				4104
				4105	<h5>Example:</h5>
				4106	<pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4107	<result> = vicmp eq <2 x i32> < i32 4, i32 0>, < i32 5, i32 0> <i>; yields: result=<2 x i32> < i32 0, i32 -1 ></i>
				4108	<result> = vicmp ult <2 x i8 > < i8 1, i8 2>, < i8 2, i8 2 > <i>; yields: result=<2 x i8> < i8 -1, i8 0 ></i>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4109	</pre>
				4110	</div>
				4111
				4112	<!-- _______________________________________________________________________ -->
				4113	<div class="doc_subsubsection">
				4114	<a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
				4115	</div>
				4116	<div class="doc_text">
				4117	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4118	<pre> <result> = vfcmp <cond> <ty> <op1>, <op2></pre>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4119	<h5>Overview:</h5>
				4120	<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
				4121	element-wise comparison of its two floating point vector operands. The output
				4122	elements have the same width as the input elements.</p>
				4123	<h5>Arguments:</h5>
				4124	<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
				4125	the condition code indicating the kind of comparison to perform. It is not
				4126	a value, just a keyword. The possible condition code are:
				4127	<ol>
				4128	<li><tt>false</tt>: no comparison, always returns false</li>
				4129	<li><tt>oeq</tt>: ordered and equal</li>
				4130	<li><tt>ogt</tt>: ordered and greater than </li>
				4131	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4132	<li><tt>olt</tt>: ordered and less than </li>
				4133	<li><tt>ole</tt>: ordered and less than or equal</li>
				4134	<li><tt>one</tt>: ordered and not equal</li>
				4135	<li><tt>ord</tt>: ordered (no nans)</li>
				4136	<li><tt>ueq</tt>: unordered or equal</li>
				4137	<li><tt>ugt</tt>: unordered or greater than </li>
				4138	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4139	<li><tt>ult</tt>: unordered or less than </li>
				4140	<li><tt>ule</tt>: unordered or less than or equal</li>
				4141	<li><tt>une</tt>: unordered or not equal</li>
				4142	<li><tt>uno</tt>: unordered (either nans)</li>
				4143	<li><tt>true</tt>: no comparison, always returns true</li>
				4144	</ol>
				4145	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				4146	<a href="#t_floating">floating point</a> typed. They must also be identical
				4147	types.</p>
				4148	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4149	<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4150	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4151	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
				4152	an identical number of elements as the values being compared, and each element
				4153	having identical with to the width of the floating point elements. The most
				4154	significant bit in each element is 1 if the element-wise comparison evaluates to
				4155	true, and is 0 otherwise. All other bits of the result are undefined. The
				4156	condition codes are evaluated identically to the
				4157	<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.
				4158
				4159	<h5>Example:</h5>
				4160	<pre>
Chris Lattner	50ad45c	2008-10-13 16:55:18 +0000	[diff] [blame]	4161	<i>; yields: result=<2 x i32> < i32 0, i32 -1 ></i>
				4162	<result> = vfcmp oeq <2 x float> < float 4, float 0 >, < float 5, float 0 >
				4163
				4164	<i>; yields: result=<2 x i64> < i64 -1, i64 0 ></i>
				4165	<result> = vfcmp ult <2 x double> < double 1, double 2 >, < double 2, double 2>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4166	</pre>
				4167	</div>
				4168
				4169	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4170	<div class="doc_subsubsection">
				4171	<a name="i_phi">'<tt>phi</tt>' Instruction</a>
				4172	</div>
				4173
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4174	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4175
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4176	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4177
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4178	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				4179	<h5>Overview:</h5>
				4180	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				4181	the SSA graph representing the function.</p>
				4182	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4183
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4184	<p>The type of the incoming values is specified with the first type
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4185	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				4186	as arguments, with one pair for each predecessor basic block of the
				4187	current block. Only values of <a href="#t_firstclass">first class</a>
				4188	type may be used as the value arguments to the PHI node. Only labels
				4189	may be used as the label arguments.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4190
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4191	<p>There must be no non-phi instructions between the start of a basic
				4192	block and the PHI instructions: i.e. PHI instructions must be first in
				4193	a basic block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4194
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4195	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4196
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4197	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				4198	specified by the pair corresponding to the predecessor basic block that executed
				4199	just prior to the current block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4200
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4201	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4202	<pre>
				4203	Loop: ; Infinite loop that counts from 0 on up...
				4204	%indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
				4205	%nextindvar = add i32 %indvar, 1
				4206	br label %Loop
				4207	</pre>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4208	</div>
				4209
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4210	<!-- _______________________________________________________________________ -->
				4211	<div class="doc_subsubsection">
				4212	<a name="i_select">'<tt>select</tt>' Instruction</a>
				4213	</div>
				4214
				4215	<div class="doc_text">
				4216
				4217	<h5>Syntax:</h5>
				4218
				4219	<pre>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4220	<result> = select <i>selty</i> <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
				4221
				4222	<i>selty</i> is either i1 or {<N x i1&gt}
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4223	</pre>
				4224
				4225	<h5>Overview:</h5>
				4226
				4227	<p>
				4228	The '<tt>select</tt>' instruction is used to choose one value based on a
				4229	condition, without branching.
				4230	</p>
				4231
				4232
				4233	<h5>Arguments:</h5>
				4234
				4235	<p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4236	The '<tt>select</tt>' instruction requires an 'i1' value or
				4237	a vector of 'i1' values indicating the
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4238	condition, and two values of the same <a href="#t_firstclass">first class</a>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4239	type. If the val1/val2 are vectors and
				4240	the condition is a scalar, then entire vectors are selected, not
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4241	individual elements.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4242	</p>
				4243
				4244	<h5>Semantics:</h5>
				4245
				4246	<p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4247	If the condition is an i1 and it evaluates to 1, the instruction returns the first
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4248	value argument; otherwise, it returns the second value argument.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4249	</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4250	<p>
				4251	If the condition is a vector of i1, then the value arguments must
				4252	be vectors of the same size, and the selection is done element
				4253	by element.
				4254	</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4255
				4256	<h5>Example:</h5>
				4257
				4258	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4259	%X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4260	</pre>
				4261	</div>
				4262
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	4263
				4264	<!-- _______________________________________________________________________ -->
				4265	<div class="doc_subsubsection">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4266	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4267	</div>
				4268
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4269	<div class="doc_text">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4270
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4271	<h5>Syntax:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4272	<pre>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	4273	<result> = [tail] call [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] <ty> [<fnty>*] <fnptrval>(<function args>) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4274	</pre>
				4275
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4276	<h5>Overview:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4277
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4278	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4279
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4280	<h5>Arguments:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4281
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4282	<p>This instruction requires several arguments:</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4283
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4284	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4285	<li>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4286	<p>The optional "tail" marker indicates whether the callee function accesses
				4287	any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4288	function call is eligible for tail call optimization. Note that calls may
				4289	be marked "tail" even if they do not occur before a <a
				4290	href="#i_ret"><tt>ret</tt></a> instruction.
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4291	</li>
				4292	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4293	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4294	convention</a> the call should use. If none is specified, the call defaults
				4295	to using C calling conventions.
				4296	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4297
				4298	<li>
				4299	<p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				4300	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				4301	and '<tt>inreg</tt>' attributes are valid here.</p>
				4302	</li>
				4303
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4304	<li>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4305	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4306	the type of the return value. Functions that return no value are marked
				4307	<tt><a href="#t_void">void</a></tt>.</p>
				4308	</li>
				4309	<li>
				4310	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4311	value being invoked. The argument types must match the types implied by
				4312	this signature. This type can be omitted if the function is not varargs
				4313	and if the function type does not return a pointer to a function.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4314	</li>
				4315	<li>
				4316	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4317	be invoked. In most cases, this is a direct function invocation, but
				4318	indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4319	to function value.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4320	</li>
				4321	<li>
				4322	<p>'<tt>function args</tt>': argument list whose types match the
Reid Spencer	a7e302a	2005-05-01 22:22:57 +0000	[diff] [blame]	4323	function signature argument types. All arguments must be of
				4324	<a href="#t_firstclass">first class</a> type. If the function signature
				4325	indicates the function accepts a variable number of arguments, the extra
				4326	arguments can be specified.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4327	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4328	<li>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	4329	<p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4330	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				4331	'<tt>readnone</tt>' attributes are valid here.</p>
				4332	</li>
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4333	</ol>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4334
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4335	<h5>Semantics:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4336
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4337	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4338	transfer to a specified function, with its incoming arguments bound to
				4339	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4340	instruction in the called function, control flow continues with the
				4341	instruction after the function call, and the return value of the
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	4342	function is bound to the result argument.
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4343
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4344	<h5>Example:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4345
				4346	<pre>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4347	%retval = call i32 @test(i32 %argc)
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4348	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4349	%X = tail call i32 @foo() <i>; yields i32</i>
				4350	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4351	call void %foo(i8 97 signext)
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4352
				4353	%struct.A = type { i32, i8 }
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4354	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	4355	%gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
				4356	%gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner	85a350f	2008-10-08 06:26:11 +0000	[diff] [blame]	4357	%Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijman	cb73d19	2008-10-07 10:03:45 +0000	[diff] [blame]	4358	%ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4359	</pre>
				4360
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4361	</div>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4362
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4363	<!-- _______________________________________________________________________ -->
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4364	<div class="doc_subsubsection">
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4365	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4366	</div>
				4367
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4368	<div class="doc_text">
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4369
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4370	<h5>Syntax:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4371
				4372	<pre>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4373	<resultval> = va_arg <va_list*> <arglist>, <argty>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4374	</pre>
				4375
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4376	<h5>Overview:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4377
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4378	<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4379	the "variable argument" area of a function call. It is used to implement the
				4380	<tt>va_arg</tt> macro in C.</p>
				4381
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4382	<h5>Arguments:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4383
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4384	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4385	the argument. It returns a value of the specified argument type and
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4386	increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4387	actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4388
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4389	<h5>Semantics:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4390
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4391	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4392	type from the specified <tt>va_list</tt> and causes the
				4393	<tt>va_list</tt> to point to the next argument. For more information,
				4394	see the variable argument handling <a href="#int_varargs">Intrinsic
				4395	Functions</a>.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4396
				4397	<p>It is legal for this instruction to be called in a function which does not
				4398	take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4399	function.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4400
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4401	<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4402	href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4403	argument.</p>
				4404
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4405	<h5>Example:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4406
				4407	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4408
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4409	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4410
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4411	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4412	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4413	<!-- *********************************************************************** -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4414
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4415	<div class="doc_text">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4416
				4417	<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4418	well known names and semantics and are required to follow certain restrictions.
				4419	Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4420	language that does not require changing all of the transformations in LLVM when
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	4421	adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4422
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4423	<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4424	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4425	begin with this prefix. Intrinsic functions must always be external functions:
				4426	you cannot define the body of intrinsic functions. Intrinsic functions may
				4427	only be used in call or invoke instructions: it is illegal to take the address
				4428	of an intrinsic function. Additionally, because intrinsic functions are part
				4429	of the LLVM language, it is required if any are added that they be documented
				4430	here.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4431
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4432	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4433	a family of functions that perform the same operation but on different data
				4434	types. Because LLVM can represent over 8 million different integer types,
				4435	overloading is used commonly to allow an intrinsic function to operate on any
				4436	integer type. One or more of the argument types or the result type can be
				4437	overloaded to accept any integer type. Argument types may also be defined as
				4438	exactly matching a previous argument's type or the result type. This allows an
				4439	intrinsic function which accepts multiple arguments, but needs all of them to
				4440	be of the same type, to only be overloaded with respect to a single argument or
				4441	the result.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4442
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4443	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4444	encoded into its function name, each preceded by a period. Only those types
				4445	which are overloaded result in a name suffix. Arguments whose type is matched
				4446	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4447	take an integer of any width and returns an integer of exactly the same integer
				4448	width. This leads to a family of functions such as
				4449	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4450	Only one type, the return type, is overloaded, and only one type suffix is
				4451	required. Because the argument's type is matched against the return type, it
				4452	does not require its own name suffix.</p>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4453
				4454	<p>To learn how to add an intrinsic function, please see the
				4455	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4456	</p>
				4457
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4458	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4459
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4460	<!-- ======================================================================= -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4461	<div class="doc_subsection">
				4462	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				4463	</div>
				4464
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4465	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4466
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4467	<p>Variable argument support is defined in LLVM with the <a
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4468	href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4469	intrinsic functions. These functions are related to the similarly
				4470	named macros defined in the <tt><stdarg.h></tt> header file.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4471
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4472	<p>All of these functions operate on arguments that use a
				4473	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4474	language reference manual does not define what this type is, so all
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4475	transformations should be prepared to handle these functions regardless of
				4476	the type used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4477
Chris Lattner	374ab30	2006-05-15 17:26:46 +0000	[diff] [blame]	4478	<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4479	instruction and the variable argument handling intrinsic functions are
				4480	used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4481
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4482	<div class="doc_code">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4483	<pre>
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4484	define i32 @test(i32 %X, ...) {
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4485	; Initialize variable argument processing
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4486	%ap = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4487	%ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4488	call void @llvm.va_start(i8* %ap2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4489
				4490	; Read a single integer argument
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4491	%tmp = va_arg i8** %ap, i32
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4492
				4493	; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4494	%aq = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4495	%aq2 = bitcast i8** %aq to i8*
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4496	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4497	call void @llvm.va_end(i8* %aq2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4498
				4499	; Stop processing of arguments.
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4500	call void @llvm.va_end(i8* %ap2)
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4501	ret i32 %tmp
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4502	}
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4503
				4504	declare void @llvm.va_start(i8*)
				4505	declare void @llvm.va_copy(i8, i8)
				4506	declare void @llvm.va_end(i8*)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4507	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4508	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4509
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4510	</div>
				4511
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4512	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4513	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4514	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4515	</div>
				4516
				4517
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4518	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4519	<h5>Syntax:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4520	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4521	<h5>Overview:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4522	<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
				4523	<tt>*<arglist></tt> for subsequent use by <tt><a
				4524	href="#i_va_arg">va_arg</a></tt>.</p>
				4525
				4526	<h5>Arguments:</h5>
				4527
				4528	<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
				4529
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4530	<h5>Semantics:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4531
				4532	<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
				4533	macro available in C. In a target-dependent way, it initializes the
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4534	<tt>va_list</tt> element to which the argument points, so that the next call to
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4535	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4536	Unlike the C <tt>va_start</tt> macro, this intrinsic does not need to know the
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4537	last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4538
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4539	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4540
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4541	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4542	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4543	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4544	</div>
				4545
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4546	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4547	<h5>Syntax:</h5>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4548	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4549	<h5>Overview:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4550
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4551	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4552	which has been initialized previously with <tt><a href="#int_va_start">llvm.va_start</a></tt>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4553	or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4554
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4555	<h5>Arguments:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4556
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4557	<p>The argument is a pointer to a <tt>va_list</tt> to destroy.</p>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4558
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4559	<h5>Semantics:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4560
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4561	<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4562	macro available in C. In a target-dependent way, it destroys the
				4563	<tt>va_list</tt> element to which the argument points. Calls to <a
				4564	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				4565	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				4566	<tt>llvm.va_end</tt>.</p>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4567
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4568	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4569
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4570	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4571	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4572	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4573	</div>
				4574
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4575	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4576
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4577	<h5>Syntax:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4578
				4579	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4580	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4581	</pre>
				4582
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4583	<h5>Overview:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4584
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4585	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				4586	from the source argument list to the destination argument list.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4587
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4588	<h5>Arguments:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4589
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4590	<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
Andrew Lenharth	d0a4c62	2005-06-22 20:38:11 +0000	[diff] [blame]	4591	The second argument is a pointer to a <tt>va_list</tt> element to copy from.</p>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4592
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4593
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4594	<h5>Semantics:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4595
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4596	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				4597	macro available in C. In a target-dependent way, it copies the source
				4598	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				4599	intrinsic is necessary because the <tt><a href="#int_va_start">
				4600	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				4601	example, memory allocation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4602
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4603	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4604
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4605	<!-- ======================================================================= -->
				4606	<div class="doc_subsection">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4607	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				4608	</div>
				4609
				4610	<div class="doc_text">
				4611
				4612	<p>
				4613	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	4614	Collection</a> (GC) requires the implementation and generation of these
				4615	intrinsics.
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4616	These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4617	stack</a>, as well as garbage collector implementations that require <a
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4618	href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4619	Front-ends for type-safe garbage collected languages should generate these
				4620	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				4621	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				4622	</p>
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	4623
				4624	<p>The garbage collection intrinsics only operate on objects in the generic
				4625	address space (address space zero).</p>
				4626
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4627	</div>
				4628
				4629	<!-- _______________________________________________________________________ -->
				4630	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4631	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4632	</div>
				4633
				4634	<div class="doc_text">
				4635
				4636	<h5>Syntax:</h5>
				4637
				4638	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4639	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4640	</pre>
				4641
				4642	<h5>Overview:</h5>
				4643
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	4644	<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4645	the code generator, and allows some metadata to be associated with it.</p>
				4646
				4647	<h5>Arguments:</h5>
				4648
				4649	<p>The first argument specifies the address of a stack object that contains the
				4650	root pointer. The second pointer (which must be either a constant or a global
				4651	value address) contains the meta-data to be associated with the root.</p>
				4652
				4653	<h5>Semantics:</h5>
				4654
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	4655	<p>At runtime, a call to this intrinsic stores a null pointer into the "ptrloc"
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4656	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4657	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				4658	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				4659	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4660
				4661	</div>
				4662
				4663
				4664	<!-- _______________________________________________________________________ -->
				4665	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4666	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4667	</div>
				4668
				4669	<div class="doc_text">
				4670
				4671	<h5>Syntax:</h5>
				4672
				4673	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4674	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4675	</pre>
				4676
				4677	<h5>Overview:</h5>
				4678
				4679	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				4680	locations, allowing garbage collector implementations that require read
				4681	barriers.</p>
				4682
				4683	<h5>Arguments:</h5>
				4684
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	4685	<p>The second argument is the address to read from, which should be an address
				4686	allocated from the garbage collector. The first object is a pointer to the
				4687	start of the referenced object, if needed by the language runtime (otherwise
				4688	null).</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4689
				4690	<h5>Semantics:</h5>
				4691
				4692	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				4693	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4694	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				4695	may only be used in a function which <a href="#gc">specifies a GC
				4696	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4697
				4698	</div>
				4699
				4700
				4701	<!-- _______________________________________________________________________ -->
				4702	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4703	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4704	</div>
				4705
				4706	<div class="doc_text">
				4707
				4708	<h5>Syntax:</h5>
				4709
				4710	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4711	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4712	</pre>
				4713
				4714	<h5>Overview:</h5>
				4715
				4716	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				4717	locations, allowing garbage collector implementations that require write
				4718	barriers (such as generational or reference counting collectors).</p>
				4719
				4720	<h5>Arguments:</h5>
				4721
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	4722	<p>The first argument is the reference to store, the second is the start of the
				4723	object to store it to, and the third is the address of the field of Obj to
				4724	store to. If the runtime does not require a pointer to the object, Obj may be
				4725	null.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4726
				4727	<h5>Semantics:</h5>
				4728
				4729	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				4730	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4731	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				4732	may only be used in a function which <a href="#gc">specifies a GC
				4733	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4734
				4735	</div>
				4736
				4737
				4738
				4739	<!-- ======================================================================= -->
				4740	<div class="doc_subsection">
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4741	<a name="int_codegen">Code Generator Intrinsics</a>
				4742	</div>
				4743
				4744	<div class="doc_text">
				4745	<p>
				4746	These intrinsics are provided by LLVM to expose special features that may only
				4747	be implemented with code generator support.
				4748	</p>
				4749
				4750	</div>
				4751
				4752	<!-- _______________________________________________________________________ -->
				4753	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4754	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4755	</div>
				4756
				4757	<div class="doc_text">
				4758
				4759	<h5>Syntax:</h5>
				4760	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4761	declare i8 *@llvm.returnaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4762	</pre>
				4763
				4764	<h5>Overview:</h5>
				4765
				4766	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	4767	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				4768	target-specific value indicating the return address of the current function
				4769	or one of its callers.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4770	</p>
				4771
				4772	<h5>Arguments:</h5>
				4773
				4774	<p>
				4775	The argument to this intrinsic indicates which function to return the address
				4776	for. Zero indicates the calling function, one indicates its caller, etc. The
				4777	argument is <b>required</b> to be a constant integer value.
				4778	</p>
				4779
				4780	<h5>Semantics:</h5>
				4781
				4782	<p>
				4783	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				4784	the return address of the specified call frame, or zero if it cannot be
				4785	identified. The value returned by this intrinsic is likely to be incorrect or 0
				4786	for arguments other than zero, so it should only be used for debugging purposes.
				4787	</p>
				4788
				4789	<p>
				4790	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	4791	aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4792	source-language caller.
				4793	</p>
				4794	</div>
				4795
				4796
				4797	<!-- _______________________________________________________________________ -->
				4798	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4799	<a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4800	</div>
				4801
				4802	<div class="doc_text">
				4803
				4804	<h5>Syntax:</h5>
				4805	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4806	declare i8 *@llvm.frameaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4807	</pre>
				4808
				4809	<h5>Overview:</h5>
				4810
				4811	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	4812	The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
				4813	target-specific frame pointer value for the specified stack frame.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4814	</p>
				4815
				4816	<h5>Arguments:</h5>
				4817
				4818	<p>
				4819	The argument to this intrinsic indicates which function to return the frame
				4820	pointer for. Zero indicates the calling function, one indicates its caller,
				4821	etc. The argument is <b>required</b> to be a constant integer value.
				4822	</p>
				4823
				4824	<h5>Semantics:</h5>
				4825
				4826	<p>
				4827	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				4828	the frame address of the specified call frame, or zero if it cannot be
				4829	identified. The value returned by this intrinsic is likely to be incorrect or 0
				4830	for arguments other than zero, so it should only be used for debugging purposes.
				4831	</p>
				4832
				4833	<p>
				4834	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	4835	aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4836	source-language caller.
				4837	</p>
				4838	</div>
				4839
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4840	<!-- _______________________________________________________________________ -->
				4841	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4842	<a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4843	</div>
				4844
				4845	<div class="doc_text">
				4846
				4847	<h5>Syntax:</h5>
				4848	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4849	declare i8 *@llvm.stacksave()
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4850	</pre>
				4851
				4852	<h5>Overview:</h5>
				4853
				4854	<p>
				4855	The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4856	the function stack, for use with <a href="#int_stackrestore">
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4857	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				4858	features like scoped automatic variable sized arrays in C99.
				4859	</p>
				4860
				4861	<h5>Semantics:</h5>
				4862
				4863	<p>
				4864	This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4865	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4866	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				4867	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				4868	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				4869	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				4870	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				4871	</p>
				4872
				4873	</div>
				4874
				4875	<!-- _______________________________________________________________________ -->
				4876	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4877	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4878	</div>
				4879
				4880	<div class="doc_text">
				4881
				4882	<h5>Syntax:</h5>
				4883	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4884	declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4885	</pre>
				4886
				4887	<h5>Overview:</h5>
				4888
				4889	<p>
				4890	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				4891	the function stack to the state it was in when the corresponding <a
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4892	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4893	useful for implementing language features like scoped automatic variable sized
				4894	arrays in C99.
				4895	</p>
				4896
				4897	<h5>Semantics:</h5>
				4898
				4899	<p>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4900	See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4901	</p>
				4902
				4903	</div>
				4904
				4905
				4906	<!-- _______________________________________________________________________ -->
				4907	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4908	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4909	</div>
				4910
				4911	<div class="doc_text">
				4912
				4913	<h5>Syntax:</h5>
				4914	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4915	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4916	</pre>
				4917
				4918	<h5>Overview:</h5>
				4919
				4920
				4921	<p>
				4922	The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4923	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				4924	no
				4925	effect on the behavior of the program but can change its performance
Chris Lattner	2a61536	2005-02-28 19:47:14 +0000	[diff] [blame]	4926	characteristics.
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4927	</p>
				4928
				4929	<h5>Arguments:</h5>
				4930
				4931	<p>
				4932	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				4933	determining if the fetch should be for a read (0) or write (1), and
				4934	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattner	aeffb4a	2005-03-07 20:31:38 +0000	[diff] [blame]	4935	locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4936	<tt>locality</tt> arguments must be constant integers.
				4937	</p>
				4938
				4939	<h5>Semantics:</h5>
				4940
				4941	<p>
				4942	This intrinsic does not modify the behavior of the program. In particular,
				4943	prefetches cannot trap and do not produce a value. On targets that support this
				4944	intrinsic, the prefetch can provide hints to the processor cache for better
				4945	performance.
				4946	</p>
				4947
				4948	</div>
				4949
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4950	<!-- _______________________________________________________________________ -->
				4951	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4952	<a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4953	</div>
				4954
				4955	<div class="doc_text">
				4956
				4957	<h5>Syntax:</h5>
				4958	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4959	declare void @llvm.pcmarker(i32 <id>)
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4960	</pre>
				4961
				4962	<h5>Overview:</h5>
				4963
				4964
				4965	<p>
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4966	The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	4967	(PC) in a region of
				4968	code to simulators and other tools. The method is target specific, but it is
				4969	expected that the marker will use exported symbols to transmit the PC of the
				4970	marker.
				4971	The marker makes no guarantees that it will remain with any specific instruction
				4972	after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattner	b3e7afd	2006-03-24 07:16:10 +0000	[diff] [blame]	4973	optimizations. The intended use is to be inserted after optimizations to allow
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4974	correlations of simulation runs.
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4975	</p>
				4976
				4977	<h5>Arguments:</h5>
				4978
				4979	<p>
				4980	<tt>id</tt> is a numerical id identifying the marker.
				4981	</p>
				4982
				4983	<h5>Semantics:</h5>
				4984
				4985	<p>
				4986	This intrinsic does not modify the behavior of the program. Backends that do not
				4987	support this intrinisic may ignore it.
				4988	</p>
				4989
				4990	</div>
				4991
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	4992	<!-- _______________________________________________________________________ -->
				4993	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4994	<a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	4995	</div>
				4996
				4997	<div class="doc_text">
				4998
				4999	<h5>Syntax:</h5>
				5000	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5001	declare i64 @llvm.readcyclecounter( )
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5002	</pre>
				5003
				5004	<h5>Overview:</h5>
				5005
				5006
				5007	<p>
				5008	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				5009	counter register (or similar low latency, high accuracy clocks) on those targets
				5010	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				5011	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				5012	should only be used for small timings.
				5013	</p>
				5014
				5015	<h5>Semantics:</h5>
				5016
				5017	<p>
				5018	When directly supported, reading the cycle counter should not modify any memory.
				5019	Implementations are allowed to either return a application specific value or a
				5020	system wide value. On backends without support, this is lowered to a constant 0.
				5021	</p>
				5022
				5023	</div>
				5024
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5025	<!-- ======================================================================= -->
				5026	<div class="doc_subsection">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5027	<a name="int_libc">Standard C Library Intrinsics</a>
				5028	</div>
				5029
				5030	<div class="doc_text">
				5031	<p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5032	LLVM provides intrinsics for a few important standard C library functions.
				5033	These intrinsics allow source-language front-ends to pass information about the
				5034	alignment of the pointer arguments to the code generator, providing opportunity
				5035	for more efficient code generation.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5036	</p>
				5037
				5038	</div>
				5039
				5040	<!-- _______________________________________________________________________ -->
				5041	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5042	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5043	</div>
				5044
				5045	<div class="doc_text">
				5046
				5047	<h5>Syntax:</h5>
				5048	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5049	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5050	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5051	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5052	i64 <len>, i32 <align>)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5053	</pre>
				5054
				5055	<h5>Overview:</h5>
				5056
				5057	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5058	The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5059	location to the destination location.
				5060	</p>
				5061
				5062	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5063	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				5064	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5065	</p>
				5066
				5067	<h5>Arguments:</h5>
				5068
				5069	<p>
				5070	The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5071	the source. The third argument is an integer argument
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5072	specifying the number of bytes to copy, and the fourth argument is the alignment
				5073	of the source and destination locations.
				5074	</p>
				5075
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5076	<p>
				5077	If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattner	f0afc2c	2006-03-04 00:02:10 +0000	[diff] [blame]	5078	the caller guarantees that both the source and destination pointers are aligned
				5079	to that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5080	</p>
				5081
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5082	<h5>Semantics:</h5>
				5083
				5084	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5085	The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5086	location to the destination location, which are not allowed to overlap. It
				5087	copies "len" bytes of memory over. If the argument is known to be aligned to
				5088	some boundary, this can be specified as the fourth argument, otherwise it should
				5089	be set to 0 or 1.
				5090	</p>
				5091	</div>
				5092
				5093
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5094	<!-- _______________________________________________________________________ -->
				5095	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5096	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5097	</div>
				5098
				5099	<div class="doc_text">
				5100
				5101	<h5>Syntax:</h5>
				5102	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5103	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5104	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5105	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5106	i64 <len>, i32 <align>)
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5107	</pre>
				5108
				5109	<h5>Overview:</h5>
				5110
				5111	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5112	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				5113	location to the destination location. It is similar to the
Chris Lattner	4b2cbcf	2008-01-06 19:51:52 +0000	[diff] [blame]	5114	'<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5115	</p>
				5116
				5117	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5118	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				5119	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5120	</p>
				5121
				5122	<h5>Arguments:</h5>
				5123
				5124	<p>
				5125	The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5126	the source. The third argument is an integer argument
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5127	specifying the number of bytes to copy, and the fourth argument is the alignment
				5128	of the source and destination locations.
				5129	</p>
				5130
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5131	<p>
				5132	If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattner	f0afc2c	2006-03-04 00:02:10 +0000	[diff] [blame]	5133	the caller guarantees that the source and destination pointers are aligned to
				5134	that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5135	</p>
				5136
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5137	<h5>Semantics:</h5>
				5138
				5139	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5140	The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5141	location to the destination location, which may overlap. It
				5142	copies "len" bytes of memory over. If the argument is known to be aligned to
				5143	some boundary, this can be specified as the fourth argument, otherwise it should
				5144	be set to 0 or 1.
				5145	</p>
				5146	</div>
				5147
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5148
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5149	<!-- _______________________________________________________________________ -->
				5150	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5151	<a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5152	</div>
				5153
				5154	<div class="doc_text">
				5155
				5156	<h5>Syntax:</h5>
				5157	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5158	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5159	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5160	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5161	i64 <len>, i32 <align>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5162	</pre>
				5163
				5164	<h5>Overview:</h5>
				5165
				5166	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5167	The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5168	byte value.
				5169	</p>
				5170
				5171	<p>
				5172	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				5173	does not return a value, and takes an extra alignment argument.
				5174	</p>
				5175
				5176	<h5>Arguments:</h5>
				5177
				5178	<p>
				5179	The first argument is a pointer to the destination to fill, the second is the
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5180	byte value to fill it with, the third argument is an integer
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5181	argument specifying the number of bytes to fill, and the fourth argument is the
				5182	known alignment of destination location.
				5183	</p>
				5184
				5185	<p>
				5186	If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattner	f0afc2c	2006-03-04 00:02:10 +0000	[diff] [blame]	5187	the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5188	</p>
				5189
				5190	<h5>Semantics:</h5>
				5191
				5192	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5193	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				5194	the
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5195	destination location. If the argument is known to be aligned to some boundary,
				5196	this can be specified as the fourth argument, otherwise it should be set to 0 or
				5197	1.
				5198	</p>
				5199	</div>
				5200
				5201
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5202	<!-- _______________________________________________________________________ -->
				5203	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5204	<a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5205	</div>
				5206
				5207	<div class="doc_text">
				5208
				5209	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5210	<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5211	floating point or vector of floating point type. Not all targets support all
				5212	types however.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5213	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5214	declare float @llvm.sqrt.f32(float %Val)
				5215	declare double @llvm.sqrt.f64(double %Val)
				5216	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				5217	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				5218	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5219	</pre>
				5220
				5221	<h5>Overview:</h5>
				5222
				5223	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5224	The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5225	returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5226	<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
Chris Lattner	103e2d7	2008-01-29 07:00:44 +0000	[diff] [blame]	5227	negative numbers other than -0.0 (which allows for better optimization, because
				5228	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5229	defined to return -0.0 like IEEE sqrt.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5230	</p>
				5231
				5232	<h5>Arguments:</h5>
				5233
				5234	<p>
				5235	The argument and return value are floating point numbers of the same type.
				5236	</p>
				5237
				5238	<h5>Semantics:</h5>
				5239
				5240	<p>
Dan Gohman	d6257fe	2007-07-16 14:37:41 +0000	[diff] [blame]	5241	This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5242	floating point number.
				5243	</p>
				5244	</div>
				5245
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5246	<!-- _______________________________________________________________________ -->
				5247	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5248	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5249	</div>
				5250
				5251	<div class="doc_text">
				5252
				5253	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5254	<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5255	floating point or vector of floating point type. Not all targets support all
				5256	types however.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5257	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5258	declare float @llvm.powi.f32(float %Val, i32 %power)
				5259	declare double @llvm.powi.f64(double %Val, i32 %power)
				5260	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5261	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5262	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5263	</pre>
				5264
				5265	<h5>Overview:</h5>
				5266
				5267	<p>
				5268	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5269	specified (positive or negative) power. The order of evaluation of
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5270	multiplications is not defined. When a vector of floating point type is
				5271	used, the second argument remains a scalar integer value.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5272	</p>
				5273
				5274	<h5>Arguments:</h5>
				5275
				5276	<p>
				5277	The second argument is an integer power, and the first is a value to raise to
				5278	that power.
				5279	</p>
				5280
				5281	<h5>Semantics:</h5>
				5282
				5283	<p>
				5284	This function returns the first value raised to the second power with an
				5285	unspecified sequence of rounding operations.</p>
				5286	</div>
				5287
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5288	<!-- _______________________________________________________________________ -->
				5289	<div class="doc_subsubsection">
				5290	<a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
				5291	</div>
				5292
				5293	<div class="doc_text">
				5294
				5295	<h5>Syntax:</h5>
				5296	<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
				5297	floating point or vector of floating point type. Not all targets support all
				5298	types however.
				5299	<pre>
				5300	declare float @llvm.sin.f32(float %Val)
				5301	declare double @llvm.sin.f64(double %Val)
				5302	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5303	declare fp128 @llvm.sin.f128(fp128 %Val)
				5304	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5305	</pre>
				5306
				5307	<h5>Overview:</h5>
				5308
				5309	<p>
				5310	The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
				5311	</p>
				5312
				5313	<h5>Arguments:</h5>
				5314
				5315	<p>
				5316	The argument and return value are floating point numbers of the same type.
				5317	</p>
				5318
				5319	<h5>Semantics:</h5>
				5320
				5321	<p>
				5322	This function returns the sine of the specified operand, returning the
				5323	same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohman	ba83b7e	2007-10-17 18:05:13 +0000	[diff] [blame]	5324	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5325	</div>
				5326
				5327	<!-- _______________________________________________________________________ -->
				5328	<div class="doc_subsubsection">
				5329	<a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
				5330	</div>
				5331
				5332	<div class="doc_text">
				5333
				5334	<h5>Syntax:</h5>
				5335	<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
				5336	floating point or vector of floating point type. Not all targets support all
				5337	types however.
				5338	<pre>
				5339	declare float @llvm.cos.f32(float %Val)
				5340	declare double @llvm.cos.f64(double %Val)
				5341	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5342	declare fp128 @llvm.cos.f128(fp128 %Val)
				5343	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5344	</pre>
				5345
				5346	<h5>Overview:</h5>
				5347
				5348	<p>
				5349	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				5350	</p>
				5351
				5352	<h5>Arguments:</h5>
				5353
				5354	<p>
				5355	The argument and return value are floating point numbers of the same type.
				5356	</p>
				5357
				5358	<h5>Semantics:</h5>
				5359
				5360	<p>
				5361	This function returns the cosine of the specified operand, returning the
				5362	same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohman	ba83b7e	2007-10-17 18:05:13 +0000	[diff] [blame]	5363	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5364	</div>
				5365
				5366	<!-- _______________________________________________________________________ -->
				5367	<div class="doc_subsubsection">
				5368	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5369	</div>
				5370
				5371	<div class="doc_text">
				5372
				5373	<h5>Syntax:</h5>
				5374	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				5375	floating point or vector of floating point type. Not all targets support all
				5376	types however.
				5377	<pre>
				5378	declare float @llvm.pow.f32(float %Val, float %Power)
				5379	declare double @llvm.pow.f64(double %Val, double %Power)
				5380	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5381	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5382	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5383	</pre>
				5384
				5385	<h5>Overview:</h5>
				5386
				5387	<p>
				5388	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5389	specified (positive or negative) power.
				5390	</p>
				5391
				5392	<h5>Arguments:</h5>
				5393
				5394	<p>
				5395	The second argument is a floating point power, and the first is a value to
				5396	raise to that power.
				5397	</p>
				5398
				5399	<h5>Semantics:</h5>
				5400
				5401	<p>
				5402	This function returns the first value raised to the second power,
				5403	returning the
				5404	same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohman	ba83b7e	2007-10-17 18:05:13 +0000	[diff] [blame]	5405	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5406	</div>
				5407
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5408
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5409	<!-- ======================================================================= -->
				5410	<div class="doc_subsection">
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5411	<a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5412	</div>
				5413
				5414	<div class="doc_text">
				5415	<p>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5416	LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5417	These allow efficient code generation for some algorithms.
				5418	</p>
				5419
				5420	</div>
				5421
				5422	<!-- _______________________________________________________________________ -->
				5423	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5424	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5425	</div>
				5426
				5427	<div class="doc_text">
				5428
				5429	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5430	<p>This is an overloaded intrinsic function. You can use bswap on any integer
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5431	type that is an even number of bytes (i.e. BitWidth % 16 == 0).
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5432	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5433	declare i16 @llvm.bswap.i16(i16 <id>)
				5434	declare i32 @llvm.bswap.i32(i32 <id>)
				5435	declare i64 @llvm.bswap.i64(i64 <id>)
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5436	</pre>
				5437
				5438	<h5>Overview:</h5>
				5439
				5440	<p>
Reid Spencer	338ea09	2007-04-02 02:25:19 +0000	[diff] [blame]	5441	The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5442	values with an even number of bytes (positive multiple of 16 bits). These are
				5443	useful for performing operations on data that is not in the target's native
				5444	byte order.
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5445	</p>
				5446
				5447	<h5>Semantics:</h5>
				5448
				5449	<p>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5450	The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5451	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5452	intrinsic returns an i32 value that has the four bytes of the input i32
				5453	swapped, so that if the input bytes are numbered 0, 1, 2, 3 then the returned
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5454	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5455	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5456	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5457	</p>
				5458
				5459	</div>
				5460
				5461	<!-- _______________________________________________________________________ -->
				5462	<div class="doc_subsubsection">
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5463	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5464	</div>
				5465
				5466	<div class="doc_text">
				5467
				5468	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5469	<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
				5470	width. Not all targets support all bit widths however.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5471	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5472	declare i8 @llvm.ctpop.i8 (i8 <src>)
				5473	declare i16 @llvm.ctpop.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5474	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5475	declare i64 @llvm.ctpop.i64(i64 <src>)
				5476	declare i256 @llvm.ctpop.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5477	</pre>
				5478
				5479	<h5>Overview:</h5>
				5480
				5481	<p>
Chris Lattner	ec6cb61	2006-01-16 22:38:59 +0000	[diff] [blame]	5482	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5483	value.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5484	</p>
				5485
				5486	<h5>Arguments:</h5>
				5487
				5488	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5489	The only argument is the value to be counted. The argument may be of any
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	5490	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5491	</p>
				5492
				5493	<h5>Semantics:</h5>
				5494
				5495	<p>
				5496	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5497	</p>
				5498	</div>
				5499
				5500	<!-- _______________________________________________________________________ -->
				5501	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5502	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5503	</div>
				5504
				5505	<div class="doc_text">
				5506
				5507	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5508	<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
				5509	integer bit width. Not all targets support all bit widths however.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5510	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5511	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5512	declare i16 @llvm.ctlz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5513	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5514	declare i64 @llvm.ctlz.i64(i64 <src>)
				5515	declare i256 @llvm.ctlz.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5516	</pre>
				5517
				5518	<h5>Overview:</h5>
				5519
				5520	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5521	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5522	leading zeros in a variable.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5523	</p>
				5524
				5525	<h5>Arguments:</h5>
				5526
				5527	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5528	The only argument is the value to be counted. The argument may be of any
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	5529	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5530	</p>
				5531
				5532	<h5>Semantics:</h5>
				5533
				5534	<p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5535	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				5536	in a variable. If the src == 0 then the result is the size in bits of the type
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5537	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5538	</p>
				5539	</div>
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5540
				5541
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5542
				5543	<!-- _______________________________________________________________________ -->
				5544	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5545	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5546	</div>
				5547
				5548	<div class="doc_text">
				5549
				5550	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5551	<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
				5552	integer bit width. Not all targets support all bit widths however.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5553	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5554	declare i8 @llvm.cttz.i8 (i8 <src>)
				5555	declare i16 @llvm.cttz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5556	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5557	declare i64 @llvm.cttz.i64(i64 <src>)
				5558	declare i256 @llvm.cttz.i256(i256 <src>)
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5559	</pre>
				5560
				5561	<h5>Overview:</h5>
				5562
				5563	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5564	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				5565	trailing zeros.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5566	</p>
				5567
				5568	<h5>Arguments:</h5>
				5569
				5570	<p>
				5571	The only argument is the value to be counted. The argument may be of any
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	5572	integer type. The return type must match the argument type.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5573	</p>
				5574
				5575	<h5>Semantics:</h5>
				5576
				5577	<p>
				5578	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				5579	in a variable. If the src == 0 then the result is the size in bits of the type
				5580	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				5581	</p>
				5582	</div>
				5583
Reid Spencer	497d93e	2007-04-01 08:27:01 +0000	[diff] [blame]	5584	<!-- _______________________________________________________________________ -->
				5585	<div class="doc_subsubsection">
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5586	<a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5587	</div>
				5588
				5589	<div class="doc_text">
				5590
				5591	<h5>Syntax:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5592	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5593	on any integer bit width.
				5594	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5595	declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
				5596	declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5597	</pre>
				5598
				5599	<h5>Overview:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5600	<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5601	range of bits from an integer value and returns them in the same bit width as
				5602	the original value.</p>
				5603
				5604	<h5>Arguments:</h5>
				5605	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5606	any bit width but they must have the same bit width. The second and third
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5607	arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5608
				5609	<h5>Semantics:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5610	<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5611	of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
				5612	<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
				5613	operates in forward mode.</p>
				5614	<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
				5615	right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5616	only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
				5617	<ol>
				5618	<li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
				5619	by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
				5620	<li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
				5621	to determine the number of bits to retain.</li>
				5622	<li>A mask of the retained bits is created by shifting a -1 value.</li>
				5623	<li>The mask is ANDed with <tt>%val</tt> to produce the result.
				5624	</ol>
Reid Spencer	d6a85b5	2007-05-14 16:14:57 +0000	[diff] [blame]	5625	<p>In reverse mode, a similar computation is made except that the bits are
				5626	returned in the reverse order. So, for example, if <tt>X</tt> has the value
				5627	<tt>i16 0x0ACF (101011001111)</tt> and we apply
				5628	<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
				5629	<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5630	</div>
				5631
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5632	<div class="doc_subsubsection">
				5633	<a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
				5634	</div>
				5635
				5636	<div class="doc_text">
				5637
				5638	<h5>Syntax:</h5>
				5639	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
				5640	on any integer bit width.
				5641	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5642	declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
				5643	declare i29 @llvm.part.set.i29.i9 (i29 %val, i9 %repl, i32 %lo, i32 %hi)
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5644	</pre>
				5645
				5646	<h5>Overview:</h5>
				5647	<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
				5648	of bits in an integer value with another integer value. It returns the integer
				5649	with the replaced bits.</p>
				5650
				5651	<h5>Arguments:</h5>
				5652	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5653	any bit width but they must have the same bit width. <tt>%val</tt> is the value
				5654	whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
				5655	integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
				5656	type since they specify only a bit index.</p>
				5657
				5658	<h5>Semantics:</h5>
				5659	<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
				5660	of operation: forwards and reverse. If <tt>%lo</tt> is greater than
				5661	<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
				5662	operates in forward mode.</p>
				5663	<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
				5664	truncating it down to the size of the replacement area or zero extending it
				5665	up to that size.</p>
				5666	<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
				5667	are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
				5668	in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
				5669	to the <tt>%hi</tt>th bit.
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	5670	<p>In reverse mode, a similar computation is made except that the bits are
				5671	reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
				5672	<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5673	<h5>Examples:</h5>
				5674	<pre>
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	5675	llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	5676	llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F
				5677	llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F
				5678	llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	5679	llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	5680	</pre>
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5681	</div>
				5682
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5683	<!-- ======================================================================= -->
				5684	<div class="doc_subsection">
				5685	<a name="int_debugger">Debugger Intrinsics</a>
				5686	</div>
				5687
				5688	<div class="doc_text">
				5689	<p>
				5690	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				5691	are described in the <a
				5692	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				5693	Debugging</a> document.
				5694	</p>
				5695	</div>
				5696
				5697
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	5698	<!-- ======================================================================= -->
				5699	<div class="doc_subsection">
				5700	<a name="int_eh">Exception Handling Intrinsics</a>
				5701	</div>
				5702
				5703	<div class="doc_text">
				5704	<p> The LLVM exception handling intrinsics (which all start with
				5705	<tt>llvm.eh.</tt> prefix), are described in the <a
				5706	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				5707	Handling</a> document. </p>
				5708	</div>
				5709
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	5710	<!-- ======================================================================= -->
				5711	<div class="doc_subsection">
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5712	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5713	</div>
				5714
				5715	<div class="doc_text">
				5716	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5717	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5718	the <tt>nest</tt> attribute, from a function. The result is a callable
				5719	function pointer lacking the nest parameter - the caller does not need
				5720	to provide a value for it. Instead, the value to use is stored in
				5721	advance in a "trampoline", a block of memory usually allocated
				5722	on the stack, which also contains code to splice the nest value into the
				5723	argument list. This is used to implement the GCC nested function address
				5724	extension.
				5725	</p>
				5726	<p>
				5727	For example, if the function is
				5728	<tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
Bill Wendling	03295ca	2007-09-22 09:23:55 +0000	[diff] [blame]	5729	pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as follows:</p>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5730	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5731	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				5732	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				5733	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				5734	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5735	</pre>
Bill Wendling	03295ca	2007-09-22 09:23:55 +0000	[diff] [blame]	5736	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				5737	to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5738	</div>
				5739
				5740	<!-- _______________________________________________________________________ -->
				5741	<div class="doc_subsubsection">
				5742	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				5743	</div>
				5744	<div class="doc_text">
				5745	<h5>Syntax:</h5>
				5746	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5747	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5748	</pre>
				5749	<h5>Overview:</h5>
				5750	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5751	This fills the memory pointed to by <tt>tramp</tt> with code
				5752	and returns a function pointer suitable for executing it.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5753	</p>
				5754	<h5>Arguments:</h5>
				5755	<p>
				5756	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				5757	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				5758	and sufficiently aligned block of memory; this memory is written to by the
Duncan Sands	c00c2ba	2007-08-22 23:39:54 +0000	[diff] [blame]	5759	intrinsic. Note that the size and the alignment are target-specific - LLVM
				5760	currently provides no portable way of determining them, so a front-end that
				5761	generates this intrinsic needs to have some target-specific knowledge.
				5762	The <tt>func</tt> argument must hold a function bitcast to an <tt>i8*</tt>.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5763	</p>
				5764	<h5>Semantics:</h5>
				5765	<p>
				5766	The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5767	dependent code, turning it into a function. A pointer to this function is
				5768	returned, but needs to be bitcast to an
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5769	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5770	before being called. The new function's signature is the same as that of
				5771	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				5772	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				5773	of pointer type. Calling the new function is equivalent to calling
				5774	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				5775	missing <tt>nest</tt> argument. If, after calling
				5776	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				5777	modified, then the effect of any later call to the returned function pointer is
				5778	undefined.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5779	</p>
				5780	</div>
				5781
				5782	<!-- ======================================================================= -->
				5783	<div class="doc_subsection">
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	5784	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				5785	</div>
				5786
				5787	<div class="doc_text">
				5788	<p>
				5789	These intrinsic functions expand the "universal IR" of LLVM to represent
				5790	hardware constructs for atomic operations and memory synchronization. This
				5791	provides an interface to the hardware, not an interface to the programmer. It
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	5792	is aimed at a low enough level to allow any programming models or APIs
				5793	(Application Programming Interfaces) which
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	5794	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				5795	hardware behavior. Just as hardware provides a "universal IR" for source
				5796	languages, it also provides a starting point for developing a "universal"
				5797	atomic operation and synchronization IR.
				5798	</p>
				5799	<p>
				5800	These do <em>not</em> form an API such as high-level threading libraries,
				5801	software transaction memory systems, atomic primitives, and intrinsic
				5802	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				5803	application libraries. The hardware interface provided by LLVM should allow
				5804	a clean implementation of all of these APIs and parallel programming models.
				5805	No one model or paradigm should be selected above others unless the hardware
				5806	itself ubiquitously does so.
				5807
				5808	</p>
				5809	</div>
				5810
				5811	<!-- _______________________________________________________________________ -->
				5812	<div class="doc_subsubsection">
				5813	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				5814	</div>
				5815	<div class="doc_text">
				5816	<h5>Syntax:</h5>
				5817	<pre>
				5818	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				5819	i1 <device> )
				5820
				5821	</pre>
				5822	<h5>Overview:</h5>
				5823	<p>
				5824	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				5825	specific pairs of memory access types.
				5826	</p>
				5827	<h5>Arguments:</h5>
				5828	<p>
				5829	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				5830	The first four arguments enables a specific barrier as listed below. The fith
				5831	argument specifies that the barrier applies to io or device or uncached memory.
				5832
				5833	</p>
				5834	<ul>
				5835	<li><tt>ll</tt>: load-load barrier</li>
				5836	<li><tt>ls</tt>: load-store barrier</li>
				5837	<li><tt>sl</tt>: store-load barrier</li>
				5838	<li><tt>ss</tt>: store-store barrier</li>
				5839	<li><tt>device</tt>: barrier applies to device and uncached memory also.
				5840	</ul>
				5841	<h5>Semantics:</h5>
				5842	<p>
				5843	This intrinsic causes the system to enforce some ordering constraints upon
				5844	the loads and stores of the program. This barrier does not indicate
				5845	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				5846	which they occur. For any of the specified pairs of load and store operations
				5847	(f.ex. load-load, or store-load), all of the first operations preceding the
				5848	barrier will complete before any of the second operations succeeding the
				5849	barrier begin. Specifically the semantics for each pairing is as follows:
				5850	</p>
				5851	<ul>
				5852	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				5853	after the barrier begins.</li>
				5854
				5855	<li><tt>ls</tt>: All loads before the barrier must complete before any
				5856	store after the barrier begins.</li>
				5857	<li><tt>ss</tt>: All stores before the barrier must complete before any
				5858	store after the barrier begins.</li>
				5859	<li><tt>sl</tt>: All stores before the barrier must complete before any
				5860	load after the barrier begins.</li>
				5861	</ul>
				5862	<p>
				5863	These semantics are applied with a logical "and" behavior when more than one
				5864	is enabled in a single memory barrier intrinsic.
				5865	</p>
				5866	<p>
				5867	Backends may implement stronger barriers than those requested when they do not
				5868	support as fine grained a barrier as requested. Some architectures do not
				5869	need all types of barriers and on such architectures, these become noops.
				5870	</p>
				5871	<h5>Example:</h5>
				5872	<pre>
				5873	%ptr = malloc i32
				5874	store i32 4, %ptr
				5875
				5876	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				5877	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				5878	<i>; guarantee the above finishes</i>
				5879	store i32 8, %ptr <i>; before this begins</i>
				5880	</pre>
				5881	</div>
				5882
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5883	<!-- _______________________________________________________________________ -->
				5884	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	5885	<a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5886	</div>
				5887	<div class="doc_text">
				5888	<h5>Syntax:</h5>
				5889	<p>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5890	This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
				5891	any integer bit width and for different address spaces. Not all targets
				5892	support all bit widths however.</p>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5893
				5894	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5895	declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				5896	declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				5897	declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				5898	declare i64 @llvm.atomic.cmp.swap.i64.p0i64( i64* <ptr>, i64 <cmp>, i64 <val> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5899
				5900	</pre>
				5901	<h5>Overview:</h5>
				5902	<p>
				5903	This loads a value in memory and compares it to a given value. If they are
				5904	equal, it stores a new value into the memory.
				5905	</p>
				5906	<h5>Arguments:</h5>
				5907	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	5908	The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result as
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5909	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				5910	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				5911	this integer type. While any bit width integer may be used, targets may only
				5912	lower representations they support in hardware.
				5913
				5914	</p>
				5915	<h5>Semantics:</h5>
				5916	<p>
				5917	This entire intrinsic must be executed atomically. It first loads the value
				5918	in memory pointed to by <tt>ptr</tt> and compares it with the value
				5919	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				5920	loaded value is yielded in all cases. This provides the equivalent of an
				5921	atomic compare-and-swap operation within the SSA framework.
				5922	</p>
				5923	<h5>Examples:</h5>
				5924
				5925	<pre>
				5926	%ptr = malloc i32
				5927	store i32 4, %ptr
				5928
				5929	%val1 = add i32 4, 4
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5930	%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5931	<i>; yields {i32}:result1 = 4</i>
				5932	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				5933	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				5934
				5935	%val2 = add i32 1, 1
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5936	%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5937	<i>; yields {i32}:result2 = 8</i>
				5938	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				5939
				5940	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				5941	</pre>
				5942	</div>
				5943
				5944	<!-- _______________________________________________________________________ -->
				5945	<div class="doc_subsubsection">
				5946	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				5947	</div>
				5948	<div class="doc_text">
				5949	<h5>Syntax:</h5>
				5950
				5951	<p>
				5952	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				5953	integer bit width. Not all targets support all bit widths however.</p>
				5954	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5955	declare i8 @llvm.atomic.swap.i8.p0i8( i8* <ptr>, i8 <val> )
				5956	declare i16 @llvm.atomic.swap.i16.p0i16( i16* <ptr>, i16 <val> )
				5957	declare i32 @llvm.atomic.swap.i32.p0i32( i32* <ptr>, i32 <val> )
				5958	declare i64 @llvm.atomic.swap.i64.p0i64( i64* <ptr>, i64 <val> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5959
				5960	</pre>
				5961	<h5>Overview:</h5>
				5962	<p>
				5963	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				5964	the value from memory. It then stores the value in <tt>val</tt> in the memory
				5965	at <tt>ptr</tt>.
				5966	</p>
				5967	<h5>Arguments:</h5>
				5968
				5969	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	5970	The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5971	<tt>val</tt> argument and the result must be integers of the same bit width.
				5972	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				5973	integer type. The targets may only lower integer representations they
				5974	support.
				5975	</p>
				5976	<h5>Semantics:</h5>
				5977	<p>
				5978	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				5979	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				5980	equivalent of an atomic swap operation within the SSA framework.
				5981
				5982	</p>
				5983	<h5>Examples:</h5>
				5984	<pre>
				5985	%ptr = malloc i32
				5986	store i32 4, %ptr
				5987
				5988	%val1 = add i32 4, 4
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5989	%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5990	<i>; yields {i32}:result1 = 4</i>
				5991	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				5992	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				5993
				5994	%val2 = add i32 1, 1
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5995	%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5996	<i>; yields {i32}:result2 = 8</i>
				5997
				5998	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				5999	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				6000	</pre>
				6001	</div>
				6002
				6003	<!-- _______________________________________________________________________ -->
				6004	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6005	<a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6006
				6007	</div>
				6008	<div class="doc_text">
				6009	<h5>Syntax:</h5>
				6010	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6011	This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on any
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6012	integer bit width. Not all targets support all bit widths however.</p>
				6013	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6014	declare i8 @llvm.atomic.load.add.i8..p0i8( i8* <ptr>, i8 <delta> )
				6015	declare i16 @llvm.atomic.load.add.i16..p0i16( i16* <ptr>, i16 <delta> )
				6016	declare i32 @llvm.atomic.load.add.i32..p0i32( i32* <ptr>, i32 <delta> )
				6017	declare i64 @llvm.atomic.load.add.i64..p0i64( i64* <ptr>, i64 <delta> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6018
				6019	</pre>
				6020	<h5>Overview:</h5>
				6021	<p>
				6022	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				6023	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6024	</p>
				6025	<h5>Arguments:</h5>
				6026	<p>
				6027
				6028	The intrinsic takes two arguments, the first a pointer to an integer value
				6029	and the second an integer value. The result is also an integer value. These
				6030	integer types can have any bit width, but they must all have the same bit
				6031	width. The targets may only lower integer representations they support.
				6032	</p>
				6033	<h5>Semantics:</h5>
				6034	<p>
				6035	This intrinsic does a series of operations atomically. It first loads the
				6036	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				6037	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6038	</p>
				6039
				6040	<h5>Examples:</h5>
				6041	<pre>
				6042	%ptr = malloc i32
				6043	store i32 4, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6044	%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6045	<i>; yields {i32}:result1 = 4</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6046	%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6047	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6048	%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6049	<i>; yields {i32}:result3 = 10</i>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6050	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6051	</pre>
				6052	</div>
				6053
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6054	<!-- _______________________________________________________________________ -->
				6055	<div class="doc_subsubsection">
				6056	<a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
				6057
				6058	</div>
				6059	<div class="doc_text">
				6060	<h5>Syntax:</h5>
				6061	<p>
				6062	This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6063	any integer bit width and for different address spaces. Not all targets
				6064	support all bit widths however.</p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6065	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6066	declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* <ptr>, i8 <delta> )
				6067	declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* <ptr>, i16 <delta> )
				6068	declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* <ptr>, i32 <delta> )
				6069	declare i64 @llvm.atomic.load.sub.i64.p0i32( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6070
				6071	</pre>
				6072	<h5>Overview:</h5>
				6073	<p>
				6074	This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
				6075	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6076	</p>
				6077	<h5>Arguments:</h5>
				6078	<p>
				6079
				6080	The intrinsic takes two arguments, the first a pointer to an integer value
				6081	and the second an integer value. The result is also an integer value. These
				6082	integer types can have any bit width, but they must all have the same bit
				6083	width. The targets may only lower integer representations they support.
				6084	</p>
				6085	<h5>Semantics:</h5>
				6086	<p>
				6087	This intrinsic does a series of operations atomically. It first loads the
				6088	value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
				6089	result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6090	</p>
				6091
				6092	<h5>Examples:</h5>
				6093	<pre>
				6094	%ptr = malloc i32
				6095	store i32 8, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6096	%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6097	<i>; yields {i32}:result1 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6098	%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6099	<i>; yields {i32}:result2 = 4</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6100	%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6101	<i>; yields {i32}:result3 = 2</i>
				6102	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
				6103	</pre>
				6104	</div>
				6105
				6106	<!-- _______________________________________________________________________ -->
				6107	<div class="doc_subsubsection">
				6108	<a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
				6109	<a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
				6110	<a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
				6111	<a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
				6112
				6113	</div>
				6114	<div class="doc_text">
				6115	<h5>Syntax:</h5>
				6116	<p>
				6117	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
				6118	<tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6119	<tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
				6120	address spaces. Not all targets support all bit widths however.</p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6121	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6122	declare i8 @llvm.atomic.load.and.i8.p0i8( i8* <ptr>, i8 <delta> )
				6123	declare i16 @llvm.atomic.load.and.i16.p0i16( i16* <ptr>, i16 <delta> )
				6124	declare i32 @llvm.atomic.load.and.i32.p0i32( i32* <ptr>, i32 <delta> )
				6125	declare i64 @llvm.atomic.load.and.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6126
				6127	</pre>
				6128
				6129	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6130	declare i8 @llvm.atomic.load.or.i8.p0i8( i8* <ptr>, i8 <delta> )
				6131	declare i16 @llvm.atomic.load.or.i16.p0i16( i16* <ptr>, i16 <delta> )
				6132	declare i32 @llvm.atomic.load.or.i32.p0i32( i32* <ptr>, i32 <delta> )
				6133	declare i64 @llvm.atomic.load.or.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6134
				6135	</pre>
				6136
				6137	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6138	declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* <ptr>, i8 <delta> )
				6139	declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* <ptr>, i16 <delta> )
				6140	declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* <ptr>, i32 <delta> )
				6141	declare i64 @llvm.atomic.load.nand.i64.p0i32( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6142
				6143	</pre>
				6144
				6145	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6146	declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* <ptr>, i8 <delta> )
				6147	declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* <ptr>, i16 <delta> )
				6148	declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* <ptr>, i32 <delta> )
				6149	declare i64 @llvm.atomic.load.xor.i64.p0i32( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6150
				6151	</pre>
				6152	<h5>Overview:</h5>
				6153	<p>
				6154	These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
				6155	the value stored in memory at <tt>ptr</tt>. It yields the original value
				6156	at <tt>ptr</tt>.
				6157	</p>
				6158	<h5>Arguments:</h5>
				6159	<p>
				6160
				6161	These intrinsics take two arguments, the first a pointer to an integer value
				6162	and the second an integer value. The result is also an integer value. These
				6163	integer types can have any bit width, but they must all have the same bit
				6164	width. The targets may only lower integer representations they support.
				6165	</p>
				6166	<h5>Semantics:</h5>
				6167	<p>
				6168	These intrinsics does a series of operations atomically. They first load the
				6169	value stored at <tt>ptr</tt>. They then do the bitwise operation
				6170	<tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
				6171	value stored at <tt>ptr</tt>.
				6172	</p>
				6173
				6174	<h5>Examples:</h5>
				6175	<pre>
				6176	%ptr = malloc i32
				6177	store i32 0x0F0F, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6178	%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6179	<i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6180	%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6181	<i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6182	%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6183	<i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6184	%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6185	<i>; yields {i32}:result3 = FF</i>
				6186	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
				6187	</pre>
				6188	</div>
				6189
				6190
				6191	<!-- _______________________________________________________________________ -->
				6192	<div class="doc_subsubsection">
				6193	<a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
				6194	<a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
				6195	<a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
				6196	<a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
				6197
				6198	</div>
				6199	<div class="doc_text">
				6200	<h5>Syntax:</h5>
				6201	<p>
				6202	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
				6203	<tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6204	<tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
				6205	address spaces. Not all targets
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6206	support all bit widths however.</p>
				6207	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6208	declare i8 @llvm.atomic.load.max.i8.p0i8( i8* <ptr>, i8 <delta> )
				6209	declare i16 @llvm.atomic.load.max.i16.p0i16( i16* <ptr>, i16 <delta> )
				6210	declare i32 @llvm.atomic.load.max.i32.p0i32( i32* <ptr>, i32 <delta> )
				6211	declare i64 @llvm.atomic.load.max.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6212
				6213	</pre>
				6214
				6215	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6216	declare i8 @llvm.atomic.load.min.i8.p0i8( i8* <ptr>, i8 <delta> )
				6217	declare i16 @llvm.atomic.load.min.i16.p0i16( i16* <ptr>, i16 <delta> )
				6218	declare i32 @llvm.atomic.load.min.i32..p0i32( i32* <ptr>, i32 <delta> )
				6219	declare i64 @llvm.atomic.load.min.i64..p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6220
				6221	</pre>
				6222
				6223	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6224	declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* <ptr>, i8 <delta> )
				6225	declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* <ptr>, i16 <delta> )
				6226	declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* <ptr>, i32 <delta> )
				6227	declare i64 @llvm.atomic.load.umax.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6228
				6229	</pre>
				6230
				6231	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6232	declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* <ptr>, i8 <delta> )
				6233	declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* <ptr>, i16 <delta> )
				6234	declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* <ptr>, i32 <delta> )
				6235	declare i64 @llvm.atomic.load.umin.i64..p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6236
				6237	</pre>
				6238	<h5>Overview:</h5>
				6239	<p>
				6240	These intrinsics takes the signed or unsigned minimum or maximum of
				6241	<tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
				6242	original value at <tt>ptr</tt>.
				6243	</p>
				6244	<h5>Arguments:</h5>
				6245	<p>
				6246
				6247	These intrinsics take two arguments, the first a pointer to an integer value
				6248	and the second an integer value. The result is also an integer value. These
				6249	integer types can have any bit width, but they must all have the same bit
				6250	width. The targets may only lower integer representations they support.
				6251	</p>
				6252	<h5>Semantics:</h5>
				6253	<p>
				6254	These intrinsics does a series of operations atomically. They first load the
				6255	value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
				6256	<tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
				6257	the original value stored at <tt>ptr</tt>.
				6258	</p>
				6259
				6260	<h5>Examples:</h5>
				6261	<pre>
				6262	%ptr = malloc i32
				6263	store i32 7, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6264	%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6265	<i>; yields {i32}:result0 = 7</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6266	%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6267	<i>; yields {i32}:result1 = -2</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6268	%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6269	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6270	%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6271	<i>; yields {i32}:result3 = 8</i>
				6272	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
				6273	</pre>
				6274	</div>
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6275
				6276	<!-- ======================================================================= -->
				6277	<div class="doc_subsection">
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6278	<a name="int_general">General Intrinsics</a>
				6279	</div>
				6280
				6281	<div class="doc_text">
				6282	<p> This class of intrinsics is designed to be generic and has
				6283	no specific purpose. </p>
				6284	</div>
				6285
				6286	<!-- _______________________________________________________________________ -->
				6287	<div class="doc_subsubsection">
				6288	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				6289	</div>
				6290
				6291	<div class="doc_text">
				6292
				6293	<h5>Syntax:</h5>
				6294	<pre>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	6295	declare void @llvm.var.annotation(i8* <val>, i8* <str>, i8* <str>, i32 <int> )
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6296	</pre>
				6297
				6298	<h5>Overview:</h5>
				6299
				6300	<p>
				6301	The '<tt>llvm.var.annotation</tt>' intrinsic
				6302	</p>
				6303
				6304	<h5>Arguments:</h5>
				6305
				6306	<p>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	6307	The first argument is a pointer to a value, the second is a pointer to a
				6308	global string, the third is a pointer to a global string which is the source
				6309	file name, and the last argument is the line number.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6310	</p>
				6311
				6312	<h5>Semantics:</h5>
				6313
				6314	<p>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6315	This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6316	This can be useful for special purpose optimizations that want to look for these
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6317	annotations. These have no other defined use, they are ignored by code
				6318	generation and optimization.
				6319	</p>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6320	</div>
				6321
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6322	<!-- _______________________________________________________________________ -->
				6323	<div class="doc_subsubsection">
Tanya Lattner	e1a8da0	2007-09-21 23:57:59 +0000	[diff] [blame]	6324	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6325	</div>
				6326
				6327	<div class="doc_text">
				6328
				6329	<h5>Syntax:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6330	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				6331	any integer bit width.
				6332	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6333	<pre>
Tanya Lattner	d3989a8	2007-09-22 00:03:01 +0000	[diff] [blame]	6334	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				6335	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				6336	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				6337	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				6338	declare i256 @llvm.annotation.i256(i256 <val>, i8* <str>, i8* <str>, i32 <int> )
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6339	</pre>
				6340
				6341	<h5>Overview:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6342
				6343	<p>
				6344	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6345	</p>
				6346
				6347	<h5>Arguments:</h5>
				6348
				6349	<p>
				6350	The first argument is an integer value (result of some expression),
				6351	the second is a pointer to a global string, the third is a pointer to a global
				6352	string which is the source file name, and the last argument is the line number.
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6353	It returns the value of the first argument.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6354	</p>
				6355
				6356	<h5>Semantics:</h5>
				6357
				6358	<p>
				6359	This intrinsic allows annotations to be put on arbitrary expressions
				6360	with arbitrary strings. This can be useful for special purpose optimizations
				6361	that want to look for these annotations. These have no other defined use, they
				6362	are ignored by code generation and optimization.
				6363	</div>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	6364
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6365	<!-- _______________________________________________________________________ -->
				6366	<div class="doc_subsubsection">
				6367	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				6368	</div>
				6369
				6370	<div class="doc_text">
				6371
				6372	<h5>Syntax:</h5>
				6373	<pre>
				6374	declare void @llvm.trap()
				6375	</pre>
				6376
				6377	<h5>Overview:</h5>
				6378
				6379	<p>
				6380	The '<tt>llvm.trap</tt>' intrinsic
				6381	</p>
				6382
				6383	<h5>Arguments:</h5>
				6384
				6385	<p>
				6386	None
				6387	</p>
				6388
				6389	<h5>Semantics:</h5>
				6390
				6391	<p>
				6392	This intrinsics is lowered to the target dependent trap instruction. If the
				6393	target does not have a trap instruction, this intrinsic will be lowered to the
				6394	call of the abort() function.
				6395	</p>
				6396	</div>
				6397
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	6398	<!-- *********************************************************************** -->
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	6399	<hr>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	6400	<address>
				6401	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
				6402	src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
				6403	<a href="http://validator.w3.org/check/referer"><img
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	6404	src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!"></a>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	6405
				6406	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer	05fe4b0	2006-03-14 05:39:39 +0000	[diff] [blame]	6407	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	6408	Last modified: $Date$
				6409	</address>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	6410
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	6411	</body>
				6412	</html>